can: kvaser_usb: Add support for Kvaser CAN/USB devices

This driver provides support for several Kvaser CAN/USB devices.
Such kind of devices supports up to three can network interfaces.

It has been tested with a Kvaser USB Leaf Light (one network interface)
connected to a pch_can interface.
The firmware version of the Kvaser device was 2.5.205.

List of Kvaser devices supported by the driver:
  - Kvaser Leaf prototype (P010v2 and v3)
  - Kvaser Leaf Light (P010v3)
  - Kvaser Leaf Professional HS
  - Kvaser Leaf SemiPro HS
  - Kvaser Leaf Professional LS
  - Kvaser Leaf Professional SWC
  - Kvaser Leaf Professional LIN
  - Kvaser Leaf SemiPro LS
  - Kvaser Leaf SemiPro SWC
  - Kvaser Memorator II, Prototype
  - Kvaser Memorator II HS/HS
  - Kvaser USBcan Professional HS/HS
  - Kvaser Leaf Light GI
  - Kvaser Leaf Professional HS (OBD-II connector)
  - Kvaser Memorator Professional HS/LS
  - Kvaser Leaf Light "China"
  - Kvaser BlackBird SemiPro
  - Kvaser OEM Mercury
  - Kvaser OEM Leaf
  - Kvaser USBcan R

Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
---
 drivers/net/can/usb/Kconfig      |   33 ++
 drivers/net/can/usb/Makefile     |    1 +
 drivers/net/can/usb/kvaser_usb.c | 1062 ++++++++++++++++++++++++++++++++++++++
 drivers/net/can/usb/kvaser_usb.h |  237 +++++++++
 4 files changed, 1333 insertions(+)
 create mode 100644 drivers/net/can/usb/kvaser_usb.c
 create mode 100644 drivers/net/can/usb/kvaser_usb.h

On 07/30/2012 07:32 AM, Olivier Sobrie wrote:
> This driver provides support for several Kvaser CAN/USB devices.
> Such kind of devices supports up to three can network interfaces.
> 
> It has been tested with a Kvaser USB Leaf Light (one network interface)
> connected to a pch_can interface.
> The firmware version of the Kvaser device was 2.5.205.

Please add linux-usb@vger.kernel.org to Cc for review of the USB part.
Please combine .h and .c file. Please make use of netdev_LEVEL() for
error printing, not dev_LEVEL().

Please review if all members of the struct kvaser_msg are properly
aligned. You never access the struct kvaser_msg_* members directly, as
they are unaligned. Please check for le16 and le32 access. You missed to
convert the bitrate.

Please check if your driver survives hot-unplugging while sending and
receiving CAN frames at maximum laod.

More comments inline,
regards, Marc

> List of Kvaser devices supported by the driver:
>   - Kvaser Leaf prototype (P010v2 and v3)
>   - Kvaser Leaf Light (P010v3)
>   - Kvaser Leaf Professional HS
>   - Kvaser Leaf SemiPro HS
>   - Kvaser Leaf Professional LS
>   - Kvaser Leaf Professional SWC
>   - Kvaser Leaf Professional LIN
>   - Kvaser Leaf SemiPro LS
>   - Kvaser Leaf SemiPro SWC
>   - Kvaser Memorator II, Prototype
>   - Kvaser Memorator II HS/HS
>   - Kvaser USBcan Professional HS/HS
>   - Kvaser Leaf Light GI
>   - Kvaser Leaf Professional HS (OBD-II connector)
>   - Kvaser Memorator Professional HS/LS
>   - Kvaser Leaf Light "China"
>   - Kvaser BlackBird SemiPro
>   - Kvaser OEM Mercury
>   - Kvaser OEM Leaf
>   - Kvaser USBcan R
> 
> Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
> ---
>  drivers/net/can/usb/Kconfig      |   33 ++
>  drivers/net/can/usb/Makefile     |    1 +
>  drivers/net/can/usb/kvaser_usb.c | 1062 ++++++++++++++++++++++++++++++++++++++
>  drivers/net/can/usb/kvaser_usb.h |  237 +++++++++
>  4 files changed, 1333 insertions(+)
>  create mode 100644 drivers/net/can/usb/kvaser_usb.c
>  create mode 100644 drivers/net/can/usb/kvaser_usb.h
> 
> diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
> index 0a68768..578955f 100644
> --- a/drivers/net/can/usb/Kconfig
> +++ b/drivers/net/can/usb/Kconfig
> @@ -13,6 +13,39 @@ config CAN_ESD_USB2
>            This driver supports the CAN-USB/2 interface
>            from esd electronic system design gmbh (http://www.esd.eu).
>  
> +config CAN_KVASER_USB
> +	tristate "Kvaser CAN/USB interface"
> +	---help---
> +	  This driver adds support for Kvaser CAN/USB devices like Kvaser
> +	  Leaf Light.
> +
> +	  The driver gives support for the following devices:
> +	    - Kvaser Leaf prototype (P010v2 and v3)
> +	    - Kvaser Leaf Light (P010v3)
> +	    - Kvaser Leaf Professional HS
> +	    - Kvaser Leaf SemiPro HS
> +	    - Kvaser Leaf Professional LS
> +	    - Kvaser Leaf Professional SWC
> +	    - Kvaser Leaf Professional LIN
> +	    - Kvaser Leaf SemiPro LS
> +	    - Kvaser Leaf SemiPro SWC
> +	    - Kvaser Memorator II, Prototype
> +	    - Kvaser Memorator II HS/HS
> +	    - Kvaser USBcan Professional HS/HS
> +	    - Kvaser Leaf Light GI
> +	    - Kvaser Leaf Professional HS (OBD-II connector)
> +	    - Kvaser Memorator Professional HS/LS
> +	    - Kvaser Leaf Light "China"
> +	    - Kvaser BlackBird SemiPro
> +	    - Kvaser OEM Mercury
> +	    - Kvaser OEM Leaf
> +	    - Kvaser USBcan R
> +
> +	  If unsure, say N.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called kvaser_usb.
> +
>  config CAN_PEAK_USB
>  	tristate "PEAK PCAN-USB/USB Pro interfaces"
>  	---help---
> diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
> index da6d1d3..80a2ee4 100644
> --- a/drivers/net/can/usb/Makefile
> +++ b/drivers/net/can/usb/Makefile
> @@ -4,6 +4,7 @@
>  
>  obj-$(CONFIG_CAN_EMS_USB) += ems_usb.o
>  obj-$(CONFIG_CAN_ESD_USB2) += esd_usb2.o
> +obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o
>  obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
>  
>  ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
> diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
> new file mode 100644
> index 0000000..4965480
> --- /dev/null
> +++ b/drivers/net/can/usb/kvaser_usb.c
> @@ -0,0 +1,1062 @@
> +/*

Please add a license statement and probably your copyright:

 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation version 2.

You also should copy the copyright from the drivers you used:

> + * Parts of this driver are based on the following:
> + *  - Kvaser linux leaf driver (version 4.78)

I just downloaded their driver and noticed that it's quite sparse on
stating the license the code is released under.
"doc/HTMLhelp/copyright.htx" is quite restrictive, the word GPL occurs 3
times, all in MODULE_LICENSE("GPL"). Running modinfo on the usbcan.ko
shows "license: GPL"

> + *  - CAN driver for esd CAN-USB/2
> + */
> +
> +#include <linux/init.h>
> +#include <linux/completion.h>
> +#include <linux/module.h>
> +#include <linux/netdevice.h>
> +#include <linux/usb.h>
> +
> +#include <linux/can.h>
> +#include <linux/can/dev.h>
> +#include <linux/can/error.h>
> +
> +#include "kvaser_usb.h"
> +
> +struct kvaser_usb_tx_urb_context {
> +	struct kvaser_usb_net_priv *priv;

Huh - how does this work without forward declaration?

> +	u32 echo_index;
> +	int dlc;
> +};
> +
> +struct kvaser_usb {
> +	struct usb_device *udev;
> +	struct kvaser_usb_net_priv *nets[MAX_NET_DEVICES];
> +
> +	struct usb_anchor rx_submitted;
> +
> +	u32 fw_version;
> +	unsigned int nchannels;
> +
> +	bool rxinitdone;
> +};
> +
> +struct kvaser_usb_net_priv {
> +	struct can_priv can;
> +
> +	atomic_t active_tx_urbs;
> +	struct usb_anchor tx_submitted;
> +	struct kvaser_usb_tx_urb_context tx_contexts[MAX_TX_URBS];
> +
> +	int open_time;

please remove open_time

> +	struct completion start_stop_comp;
> +
> +	struct kvaser_usb *dev;
> +	struct net_device *netdev;
> +	int channel;
> +	struct can_berr_counter bec;
> +};
> +
> +static struct usb_device_id kvaser_usb_table[] = {
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_DEVEL_PRODUCT_ID) },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_PRODUCT_ID) },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_PRODUCT_ID),
> +		.driver_info = KVASER_HAS_SILENT_MODE },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_PRODUCT_ID),
> +		.driver_info = KVASER_HAS_SILENT_MODE },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_LS_PRODUCT_ID),
> +		.driver_info = KVASER_HAS_SILENT_MODE },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_SWC_PRODUCT_ID),
> +		.driver_info = KVASER_HAS_SILENT_MODE },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_LIN_PRODUCT_ID),
> +		.driver_info = KVASER_HAS_SILENT_MODE },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_LS_PRODUCT_ID),
> +		.driver_info = KVASER_HAS_SILENT_MODE },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_SWC_PRODUCT_ID),
> +		.driver_info = KVASER_HAS_SILENT_MODE },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_DEVEL_PRODUCT_ID),
> +		.driver_info = KVASER_HAS_SILENT_MODE },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_HSHS_PRODUCT_ID),
> +		.driver_info = KVASER_HAS_SILENT_MODE },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_UPRO_HSHS_PRODUCT_ID) },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_GI_PRODUCT_ID) },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_OBDII_PRODUCT_ID),
> +		.driver_info = KVASER_HAS_SILENT_MODE },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_HSLS_PRODUCT_ID) },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_CH_PRODUCT_ID) },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_BLACKBIRD_SPRO_PRODUCT_ID) },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_OEM_MERCURY_PRODUCT_ID) },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_OEM_LEAF_PRODUCT_ID) },
> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_CAN_R_PRODUCT_ID) },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(usb, kvaser_usb_table);
> +
> +static int kvaser_usb_send_msg(const struct kvaser_usb *dev,
> +			       struct kvaser_msg *msg)
inline?
> +{
> +	int actual_len;
> +
> +	return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 1),
                                                                  ^
Can you please introduce a #define for this.

> +			    msg, msg->len, &actual_len, USB_SEND_TIMEOUT);
> +}
> +
> +static int kvaser_usb_wait_msg(const struct kvaser_usb *dev, u8 id,
> +			       struct kvaser_msg *msg)
> +{
> +	struct kvaser_msg *tmp;
> +	void *buf;
> +	int actual_len;
> +	int err;
> +	int pos = 0;
> +
> +	buf = kzalloc(RX_BUFFER_SIZE, GFP_KERNEL);
> +	if (!buf)
> +		return -ENOMEM;
> +
> +	err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, 129),
                                                                 ^^^
dito

> +			   buf, RX_BUFFER_SIZE, &actual_len,
> +			   USB_RECEIVE_TIMEOUT);
> +	if (err < 0) {
> +		kfree(buf);
> +		return err;
> +	}
> +
> +	while (pos < actual_len) {

Please check that pos + sizeof(*msg) is < actual_len, as you fill access
it later.

> +		tmp = buf + pos;
> +
> +		if (!tmp->len)
> +			break;
> +
> +		if (tmp->id == id) {
> +			memcpy(msg, tmp, sizeof(*msg));
> +			kfree(buf);
> +			return 0;
> +		}
> +
> +		pos += tmp->len;
> +	}
> +
> +	kfree(buf);
> +
> +	return -EINVAL;
> +}
> +
> +static int kvaser_usb_send_simple_msg(const struct kvaser_usb *dev,
> +				      u8 msg_id, int channel)
> +{
> +	struct kvaser_msg msg;
> +	int err;
> +
> +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_simple);
> +	msg.id = msg_id;
> +	msg.u.simple.channel = channel;
> +	msg.u.simple.tid = 0xff;

Please use C99 struct initializer.

struct kvaser_msg msg = {
	.len = ,
	.id =,
};


> +
> +	err = kvaser_usb_send_msg(dev, &msg);

	just:
	return err;

> +	if (err)
> +		return err;
> +
> +	return 0;
> +}
> +
> +static int kvaser_usb_get_software_info(struct kvaser_usb *dev)
> +{
> +	struct kvaser_msg msg;
> +	int err;
> +
> +	err = kvaser_usb_send_simple_msg(dev, CMD_GET_SOFTWARE_INFO, 0);
> +	if (err)
> +		return err;
> +
> +	err = kvaser_usb_wait_msg(dev, CMD_GET_SOFTWARE_INFO_REPLY, &msg);
> +	if (err)
> +		return err;
> +
> +	dev->fw_version = le32_to_cpu(msg.u.softinfo.fw_version);
> +
> +	return 0;
> +}
> +
> +static int kvaser_usb_get_card_info(struct kvaser_usb *dev)
> +{
> +	struct kvaser_msg msg;
> +	int err;
> +
> +	err = kvaser_usb_send_simple_msg(dev, CMD_GET_CARD_INFO, 0);
> +	if (err)
> +		return err;
> +
> +	err = kvaser_usb_wait_msg(dev, CMD_GET_CARD_INFO_REPLY, &msg);
> +	if (err)
> +		return err;
> +
> +	dev->nchannels = msg.u.cardinfo.nchannels;
> +
> +	return 0;
> +}
> +
> +static void kvaser_usb_tx_acknowledge(const struct kvaser_usb *dev,
> +				      const struct kvaser_msg *msg)
> +{
> +	struct net_device_stats *stats;
> +	struct kvaser_usb_tx_urb_context *context;
> +	struct kvaser_usb_net_priv *priv;
> +	u8 channel = msg->u.tx_acknowledge.channel;
> +	u8 tid = msg->u.tx_acknowledge.tid;
> +
> +	if (channel >= dev->nchannels) {
> +		dev_err(dev->udev->dev.parent,
> +			"Invalid channel number (%d)\n", channel);
> +		return;
> +	}

can you do a check for (channel >= dev->nchannels), in a central place?
e.g. kvaser_usb_handle_message()?

> +
> +	priv = dev->nets[channel];
> +
> +	if (!netif_device_present(priv->netdev))
> +		return;
> +
> +	stats = &priv->netdev->stats;
> +
> +	context = &priv->tx_contexts[tid % MAX_TX_URBS];
> +
> +	/*
> +	 * It looks like the firmware never sets the flags field of the
> +	 * tx_acknowledge frame and never reports a transmit failure.
> +	 * If the can message can't be transmited (e.g. incompatible
> +	 * bitrates), a frame CMD_CAN_ERROR_EVENT is sent (with a null
> +	 * tid) and the firmware tries to transmit again the packet until
> +	 * it succeeds. Once the packet is successfully transmitted, then
> +	 * the tx_acknowledge frame is sent.
> +	 */
> +
> +	stats->tx_packets++;
> +	stats->tx_bytes += context->dlc;
> +	can_get_echo_skb(priv->netdev, context->echo_index);
> +
> +	context->echo_index = MAX_TX_URBS;
> +	atomic_dec(&priv->active_tx_urbs);
> +
> +	netif_wake_queue(priv->netdev);
> +}
> +
> +static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
> +				const struct kvaser_msg *msg)
> +{
> +	struct can_frame *cf;
> +	struct sk_buff *skb;
> +	struct net_device_stats *stats;
> +	struct kvaser_usb_net_priv *priv;
> +	u8 channel, status, txerr, rxerr;
> +
> +	if (msg->id == CMD_CAN_ERROR_EVENT) {
> +		channel = msg->u.error_event.channel;
> +		status =  msg->u.error_event.status;
> +		txerr = msg->u.error_event.tx_errors_count;
> +		rxerr = msg->u.error_event.rx_errors_count;
> +	} else {
> +		channel = msg->u.chip_state_event.channel;
> +		status =  msg->u.chip_state_event.status;
> +		txerr = msg->u.chip_state_event.tx_errors_count;
> +		rxerr = msg->u.chip_state_event.rx_errors_count;
> +	}
> +
> +	if (channel >= dev->nchannels) {
> +		dev_err(dev->udev->dev.parent,
> +			"Invalid channel number (%d)\n", channel);
> +		return;
> +	}
> +
> +	priv = dev->nets[channel];
> +	stats = &priv->netdev->stats;
> +
> +	skb = alloc_can_err_skb(priv->netdev, &cf);
> +	if (!skb) {
> +		stats->rx_dropped++;
> +		return;
> +	}
> +
> +	if ((status & M16C_STATE_BUS_OFF) ||
> +	    (status & M16C_STATE_BUS_RESET)) {
> +		priv->can.state = CAN_STATE_BUS_OFF;
> +		cf->can_id |= CAN_ERR_BUSOFF;
> +		can_bus_off(priv->netdev);
> +	} else if (status & M16C_STATE_BUS_ERROR) {
> +		priv->can.state = CAN_STATE_ERROR_WARNING;
> +		priv->can.can_stats.error_warning++;
> +	} else if (status & M16C_STATE_BUS_PASSIVE) {
> +		priv->can.state = CAN_STATE_ERROR_PASSIVE;
> +		priv->can.can_stats.error_passive++;
> +	} else {
> +		priv->can.state = CAN_STATE_ERROR_ACTIVE;
> +		cf->can_id |= CAN_ERR_PROT;
> +		cf->data[2] = CAN_ERR_PROT_ACTIVE;
> +	}
> +
> +	if (msg->id == CMD_CAN_ERROR_EVENT) {
> +		u8 error_factor = msg->u.error_event.error_factor;
> +
> +		priv->can.can_stats.bus_error++;
> +		stats->rx_errors++;
> +
> +		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
> +
> +		if ((priv->can.state == CAN_STATE_ERROR_WARNING) ||
> +		    (priv->can.state == CAN_STATE_ERROR_PASSIVE)) {
> +			cf->data[1] = (txerr > rxerr) ?
> +				CAN_ERR_CRTL_TX_PASSIVE
> +				: CAN_ERR_CRTL_RX_PASSIVE;
> +		}
> +
> +		if (error_factor & M16C_EF_ACKE)
> +			cf->data[3] |= (CAN_ERR_PROT_LOC_ACK |
> +					CAN_ERR_PROT_LOC_ACK_DEL);
> +		if (error_factor & M16C_EF_CRCE)
> +			cf->data[3] |= (CAN_ERR_PROT_LOC_CRC_SEQ |
> +					CAN_ERR_PROT_LOC_CRC_DEL);
> +		if (error_factor & M16C_EF_FORME)
> +			cf->data[2] |= CAN_ERR_PROT_FORM;
> +		if (error_factor & M16C_EF_STFE)
> +			cf->data[2] |= CAN_ERR_PROT_STUFF;
> +		if (error_factor & M16C_EF_BITE0)
> +			cf->data[2] |= CAN_ERR_PROT_BIT0;
> +		if (error_factor & M16C_EF_BITE1)
> +			cf->data[2] |= CAN_ERR_PROT_BIT1;
> +		if (error_factor & M16C_EF_TRE)
> +			cf->data[2] |= CAN_ERR_PROT_TX;
> +	}
> +
> +	cf->data[6] = txerr;
> +	cf->data[7] = rxerr;
> +
> +	netif_rx(skb);
> +
> +	priv->bec.txerr = txerr;
> +	priv->bec.rxerr = rxerr;
> +
> +	stats->rx_packets++;
> +	stats->rx_bytes += cf->can_dlc;
> +}
> +
> +static void kvaser_usb_rx_can_msg(const struct kvaser_usb *dev,
> +				  const struct kvaser_msg *msg)
> +{
> +	struct kvaser_usb_net_priv *priv;
> +	struct can_frame *cf;
> +	struct sk_buff *skb;
> +	struct net_device_stats *stats;
> +	u8 channel = msg->u.rx_can.channel;
> +
> +	if (channel >= dev->nchannels) {
> +		dev_err(dev->udev->dev.parent,
> +			"Invalid channel number (%d)\n", channel);
> +		return;
> +	}
> +
> +	priv = dev->nets[channel];
> +	stats = &priv->netdev->stats;
> +
> +	skb = alloc_can_skb(priv->netdev, &cf);
> +	if (skb == NULL) {
> +		stats->tx_dropped++;
> +		return;
> +	}
> +
> +	cf->can_id = ((msg->u.rx_can.msg[0] & 0x1f) << 6) |
> +		     (msg->u.rx_can.msg[1] & 0x3f);
> +	cf->can_dlc = get_can_dlc(msg->u.rx_can.msg[5]);
> +
> +	if (msg->id == CMD_RX_EXT_MESSAGE) {
> +		cf->can_id <<= 18;
> +		cf->can_id += ((msg->u.rx_can.msg[2] & 0x0f) << 14) |
                           |=

is more appropriate here

> +			      ((msg->u.rx_can.msg[3] & 0xff) << 6) |
> +			      (msg->u.rx_can.msg[4] & 0x3f);
> +		cf->can_id |= CAN_EFF_FLAG;
> +	}
> +
> +	if (msg->u.rx_can.flag & MSG_FLAG_REMOTE_FRAME) {
> +		cf->can_id |= CAN_RTR_FLAG;
> +	} else if (msg->u.rx_can.flag & (MSG_FLAG_ERROR_FRAME |
> +						MSG_FLAG_NERR)) {
> +		cf->can_id |= CAN_ERR_FLAG;
> +		cf->can_dlc = CAN_ERR_DLC;

What kind of error is this? Can you set cf->data? What about the
original cd->can_id? What about the stats->rx_*error* stats?

> +	} else if (msg->u.rx_can.flag & MSG_FLAG_OVERRUN) {
> +		cf->can_id = CAN_ERR_FLAG | CAN_ERR_CRTL;
> +		cf->can_dlc = CAN_ERR_DLC;
> +		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
> +
> +		stats->rx_over_errors++;
> +		stats->rx_errors++;
> +	} else if (!msg->u.rx_can.flag) {
> +		memcpy(cf->data, &msg->u.rx_can.msg[6], cf->can_dlc);
> +	} else {
> +		kfree_skb(skb);
> +		return;
> +	}
> +
> +	netif_rx(skb);
> +
> +	stats->rx_packets++;
> +	stats->rx_bytes += cf->can_dlc;
> +}
> +
> +static void kvaser_usb_start_stop_chip_reply(const struct kvaser_usb *dev,
> +					     const struct kvaser_msg *msg)
> +{
> +	struct kvaser_usb_net_priv *priv;
> +	u8 channel = msg->u.simple.channel;
> +
> +	if (channel >= dev->nchannels) {
> +		dev_err(dev->udev->dev.parent,
> +			"Invalid channel number (%d)\n", channel);
> +		return;
> +	}
> +
> +	priv = dev->nets[channel];
> +
> +	complete(&priv->start_stop_comp);
> +}
> +
> +static void kvaser_usb_handle_message(const struct kvaser_usb *dev,
> +				      const struct kvaser_msg *msg)
> +{
> +	switch (msg->id) {
> +	case CMD_START_CHIP_REPLY:
> +	case CMD_STOP_CHIP_REPLY:
> +		kvaser_usb_start_stop_chip_reply(dev, msg);
> +		break;
> +
> +	case CMD_RX_STD_MESSAGE:
> +	case CMD_RX_EXT_MESSAGE:
> +		kvaser_usb_rx_can_msg(dev, msg);
> +		break;
> +
> +	case CMD_CHIP_STATE_EVENT:
> +	case CMD_CAN_ERROR_EVENT:
> +		kvaser_usb_rx_error(dev, msg);
> +		break;
> +
> +	case CMD_TX_ACKNOWLEDGE:
> +		kvaser_usb_tx_acknowledge(dev, msg);
> +		break;
> +
> +	default:
> +		dev_warn(dev->udev->dev.parent,
> +			 "Unhandled message (%d)\n", msg->id);
> +		break;
> +	}
> +}
> +
> +static void kvaser_usb_read_bulk_callback(struct urb *urb)
> +{
> +	struct kvaser_usb *dev = urb->context;
> +	struct kvaser_msg *msg;
> +	int pos = 0;
> +	int err, i;
> +
> +	switch (urb->status) {
> +	case 0:
> +		break;
> +	case -ENOENT:
> +	case -ESHUTDOWN:
> +		return;
> +	default:
> +		dev_info(dev->udev->dev.parent, "Rx URB aborted (%d)\n",
> +			 urb->status);
> +		goto resubmit_urb;
> +	}
> +
> +	while (pos < urb->actual_length) {

please check here for pos + sizeof(*msg), too

> +		msg = urb->transfer_buffer + pos;
> +
> +		if (!msg->len)
> +			break;
> +
> +		kvaser_usb_handle_message(dev, msg);
> +
> +		if (pos > urb->actual_length) {
> +			dev_err(dev->udev->dev.parent, "Format error\n");
> +			break;
> +		}
> +
> +		pos += msg->len;
> +	}
> +
> +resubmit_urb:
> +	usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 129),
                                                                     ^^^

use #define

> +			  urb->transfer_buffer, RX_BUFFER_SIZE,
> +			  kvaser_usb_read_bulk_callback, dev);
> +
> +	err = usb_submit_urb(urb, GFP_ATOMIC);
> +	if (err == -ENODEV) {
> +		for (i = 0; i < dev->nchannels; i++) {
> +			if (!dev->nets[i])
> +				continue;
> +
> +			netif_device_detach(dev->nets[i]->netdev);
> +		}
> +	} else if (err) {
> +		dev_err(dev->udev->dev.parent,
> +			"Failed resubmitting read bulk urb: %d\n", err);
> +	}
> +
> +	return;
> +}
> +
> +static int kvaser_usb_setup_rx_urbs(struct kvaser_usb *dev)
> +{
> +	int i, err = 0;
> +
> +	if (dev->rxinitdone)
> +		return 0;
> +
> +	for (i = 0; i < MAX_RX_URBS; i++) {
> +		struct urb *urb = NULL;
> +		u8 *buf = NULL;
> +
> +		urb = usb_alloc_urb(0, GFP_KERNEL);
> +		if (!urb) {
> +			dev_warn(dev->udev->dev.parent,
> +				 "No memory left for URBs\n");
> +			err = -ENOMEM;
> +			break;
> +		}
> +
> +		buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE,
> +					 GFP_KERNEL, &urb->transfer_dma);
> +		if (!buf) {
> +			dev_warn(dev->udev->dev.parent,
> +				 "No memory left for USB buffer\n");
> +			usb_free_urb(urb);
> +			err = -ENOMEM;
> +			break;
> +		}
> +
> +		usb_fill_bulk_urb(urb, dev->udev,
> +				  usb_rcvbulkpipe(dev->udev, 129),

use #define

> +				  buf, RX_BUFFER_SIZE,
> +				  kvaser_usb_read_bulk_callback, dev);
> +		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> +		usb_anchor_urb(urb, &dev->rx_submitted);
> +
> +		err = usb_submit_urb(urb, GFP_KERNEL);
> +		if (err) {
> +			usb_unanchor_urb(urb);
> +			usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
> +					  urb->transfer_dma);
> +			break;
> +		}
> +
> +		usb_free_urb(urb);
> +	}
> +
> +	if (i == 0) {
> +		dev_warn(dev->udev->dev.parent,
> +			 "Cannot setup read URBs, error %d\n", err);
> +		return err;
> +	} else if (i < MAX_RX_URBS) {
> +		dev_warn(dev->udev->dev.parent,
> +			 "RX performances may be slow\n");
> +	}
> +
> +	dev->rxinitdone = true;
> +
> +	return 0;
> +}
> +
> +static int kvaser_usb_set_opt_mode(const struct kvaser_usb_net_priv *priv)
> +{
> +	struct kvaser_msg msg;
> +
> +	memset(&msg, 0x00, sizeof(msg));
> +	msg.id = CMD_SET_CTRL_MODE;
> +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_ctrl_mode);
> +	msg.u.ctrl_mode.tid = 0xff;
> +	msg.u.ctrl_mode.channel = priv->channel;

please use C99 struct initializers

> +
> +	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
> +		msg.u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_SILENT;
> +	else
> +		msg.u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_NORMAL;
> +
> +	return kvaser_usb_send_msg(priv->dev, &msg);
> +}
> +
> +static int kvaser_usb_start_chip(struct kvaser_usb_net_priv *priv)
> +{
> +	int err;
> +
> +	init_completion(&priv->start_stop_comp);
> +
> +	err = kvaser_usb_send_simple_msg(priv->dev, CMD_START_CHIP,
> +					 priv->channel);
> +	if (err)
> +		return err;
> +
> +	if (!wait_for_completion_timeout(&priv->start_stop_comp,
> +					 msecs_to_jiffies(START_TIMEOUT)))
> +		return -ETIMEDOUT;
> +
> +	return 0;
> +}
> +
> +static int kvaser_usb_open(struct net_device *netdev)
> +{
> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> +	struct kvaser_usb *dev = priv->dev;
> +	int err;
> +
> +	err = open_candev(netdev);
> +	if (err)
> +		return err;
> +
> +	err = kvaser_usb_setup_rx_urbs(dev);
> +	if (err)
> +		return err;
> +
> +	err = kvaser_usb_set_opt_mode(priv);
> +	if (err)
> +		return err;
> +
> +	err = kvaser_usb_start_chip(priv);
> +	if (err) {
> +		netdev_warn(netdev, "Cannot start device, error %d\n", err);
> +		close_candev(netdev);
> +		return err;
> +	}
> +
> +	priv->can.state = CAN_STATE_ERROR_ACTIVE;
> +	priv->open_time = jiffies;
> +	netif_start_queue(netdev);
> +
> +	return 0;
> +}
> +
> +static void kvaser_usb_unlink_tx_urbs(struct kvaser_usb_net_priv *priv)
> +{
> +	int i;
> +
> +	usb_kill_anchored_urbs(&priv->tx_submitted);
> +	atomic_set(&priv->active_tx_urbs, 0);
> +
> +	for (i = 0; i < MAX_TX_URBS; i++)
ARRAY_SIZE(priv->tx_contexts) instead of MAX_TX_URBS
> +		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
> +}
> +
> +static void kvaser_usb_unlink_all_urbs(struct kvaser_usb *dev)
> +{
> +	int i;
> +
> +	usb_kill_anchored_urbs(&dev->rx_submitted);
> +
> +	for (i = 0; i < MAX_NET_DEVICES; i++) {
ARRAY_SIZE()
> +		struct kvaser_usb_net_priv *priv = dev->nets[i];
> +
> +		if (priv)
> +			kvaser_usb_unlink_tx_urbs(priv);
> +	}
> +}
> +
> +static int kvaser_usb_stop_chip(struct kvaser_usb_net_priv *priv)
> +{
> +	int err;
> +
> +	init_completion(&priv->start_stop_comp);
> +
> +	err = kvaser_usb_send_simple_msg(priv->dev, CMD_STOP_CHIP,
> +					 priv->channel);
> +	if (err)
> +		return err;
> +
> +	if (!wait_for_completion_timeout(&priv->start_stop_comp,
> +					 msecs_to_jiffies(STOP_TIMEOUT)))
> +		return -ETIMEDOUT;
> +
> +	return 0;
> +}
> +
> +static int kvaser_usb_flush_queue(struct kvaser_usb_net_priv *priv)
> +{
> +	struct kvaser_msg msg;
> +
> +	memset(&msg, 0x00, sizeof(msg));
> +	msg.id = CMD_FLUSH_QUEUE;
> +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_flush_queue);
> +	msg.u.flush_queue.channel = priv->channel;
C99 initialziers, please
> +
> +	return kvaser_usb_send_msg(priv->dev, &msg);
> +}
> +
> +static int kvaser_usb_close(struct net_device *netdev)
> +{
> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> +	int err;
> +
> +	netif_stop_queue(netdev);
> +
> +	err = kvaser_usb_flush_queue(priv);
> +	if (err)
> +		netdev_warn(netdev, "Cannot flush queue, error %d\n", err);
> +
> +	err = kvaser_usb_stop_chip(priv);
> +	if (err) {
> +		netdev_warn(netdev, "Cannot stop device, error %d\n", err);
> +		return err;
> +	}
> +
> +	kvaser_usb_unlink_tx_urbs(priv);
> +
> +	priv->can.state = CAN_STATE_STOPPED;
> +	close_candev(priv->netdev);
> +	priv->open_time = 0;
> +
> +	return 0;
> +}
> +
> +static void kvaser_usb_write_bulk_callback(struct urb *urb)
> +{
> +	struct kvaser_usb_tx_urb_context *context = urb->context;
> +	struct kvaser_usb_net_priv *priv;
> +	struct net_device *netdev;
> +
> +	if (WARN_ON(!context))
> +		return;
> +
> +	priv = context->priv;
> +	netdev = priv->netdev;
> +
> +	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
> +			  urb->transfer_buffer, urb->transfer_dma);
> +
> +	if (!netif_device_present(netdev))
> +		return;
> +
> +	if (urb->status)
> +		netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
> +
> +	netdev->trans_start = jiffies;

Is trans_start needed? at least for non-usb devices it works without.

> +}
> +
> +static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
> +					 struct net_device *netdev)
> +{
> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> +	struct kvaser_usb *dev = priv->dev;
> +	struct net_device_stats *stats = &netdev->stats;
> +	struct can_frame *cf = (struct can_frame *)skb->data;
> +	struct kvaser_usb_tx_urb_context *context = NULL;
> +	struct urb *urb;
> +	void *buf;
> +	struct kvaser_msg *msg;
> +	int i, err;
> +	int ret = NETDEV_TX_OK;
> +
> +	if (can_dropped_invalid_skb(netdev, skb))
> +		return NETDEV_TX_OK;
> +
> +	urb = usb_alloc_urb(0, GFP_ATOMIC);
> +	if (!urb) {
> +		netdev_err(netdev, "No memory left for URBs\n");
> +		stats->tx_dropped++;
> +		dev_kfree_skb(skb);
> +		goto nourbmem;
> +	}
> +
> +	buf = usb_alloc_coherent(dev->udev, sizeof(struct kvaser_msg),
> +				 GFP_ATOMIC, &urb->transfer_dma);
> +	if (!buf) {
> +		netdev_err(netdev, "No memory left for USB buffer\n");
> +		stats->tx_dropped++;
> +		dev_kfree_skb(skb);
> +		goto nobufmem;
> +	}
> +
> +	msg = (struct kvaser_msg *)buf;
> +	msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_tx_can);
> +	msg->u.tx_can.flags = 0;
> +	msg->u.tx_can.channel = priv->channel;
> +
> +	if (cf->can_id & CAN_EFF_FLAG) {
> +		msg->id = CMD_TX_EXT_MESSAGE;
> +		msg->u.tx_can.msg[0] = (cf->can_id >> 24) & 0x1f;
> +		msg->u.tx_can.msg[1] = (cf->can_id >> 18) & 0x3f;
> +		msg->u.tx_can.msg[2] = (cf->can_id >> 14) & 0x0f;
> +		msg->u.tx_can.msg[3] = (cf->can_id >> 6) & 0xff;
> +		msg->u.tx_can.msg[4] = cf->can_id & 0x3f;
> +	} else {
> +		msg->id = CMD_TX_STD_MESSAGE;
> +		msg->u.tx_can.msg[0] = (cf->can_id >> 6) & 0x1f;
> +		msg->u.tx_can.msg[1] = cf->can_id & 0x3f;
> +	}
> +
> +	msg->u.tx_can.msg[5] = cf->can_dlc;
> +	memcpy(&msg->u.tx_can.msg[6], cf->data, cf->can_dlc);
> +
> +	if (cf->can_id & CAN_RTR_FLAG)
> +		msg->u.tx_can.flags |= MSG_FLAG_REMOTE_FRAME;
> +
> +	for (i = 0; i < MAX_TX_URBS; i++) {
ARRAY_SIZE
> +		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
> +			context = &priv->tx_contexts[i];
> +			break;
> +		}
> +	}
> +
> +	if (!context) {
> +		netdev_warn(netdev, "cannot find free context\n");
> +		ret =  NETDEV_TX_BUSY;
> +		goto releasebuf;
> +	}
> +
> +	context->priv = priv;
> +	context->echo_index = i;
> +	context->dlc = cf->can_dlc;
> +
> +	msg->u.tx_can.tid = context->echo_index;
> +
> +	usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
> +			  buf, msg->len,
> +			  kvaser_usb_write_bulk_callback, context);
> +	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> +	usb_anchor_urb(urb, &priv->tx_submitted);
> +
> +	can_put_echo_skb(skb, netdev, context->echo_index);
> +
> +	atomic_inc(&priv->active_tx_urbs);
> +
> +	if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
> +		netif_stop_queue(netdev);
> +
> +	err = usb_submit_urb(urb, GFP_ATOMIC);
> +	if (unlikely(err)) {
> +		can_free_echo_skb(netdev, context->echo_index);
> +
> +		atomic_dec(&priv->active_tx_urbs);
> +		usb_unanchor_urb(urb);
> +
> +		stats->tx_dropped++;
> +
> +		if (err == -ENODEV)
> +			netif_device_detach(netdev);
> +		else
> +			netdev_warn(netdev, "Failed tx_urb %d\n", err);
> +
> +		goto releasebuf;
> +	}
> +
> +	netdev->trans_start = jiffies;
> +
> +	usb_free_urb(urb);
> +
> +	return NETDEV_TX_OK;
> +
> +releasebuf:
> +	usb_free_coherent(dev->udev, sizeof(struct kvaser_msg),
> +			  buf, urb->transfer_dma);
> +nobufmem:
> +	usb_free_urb(urb);
> +nourbmem:
> +	return ret;
> +}
> +
> +static const struct net_device_ops kvaser_usb_netdev_ops = {
> +	.ndo_open = kvaser_usb_open,
> +	.ndo_stop = kvaser_usb_close,
> +	.ndo_start_xmit = kvaser_usb_start_xmit,
> +};
> +
> +static struct can_bittiming_const kvaser_usb_bittiming_const = {
> +	.name = "kvaser_usb",
> +	.tseg1_min = KVASER_USB_TSEG1_MIN,
> +	.tseg1_max = KVASER_USB_TSEG1_MAX,
> +	.tseg2_min = KVASER_USB_TSEG2_MIN,
> +	.tseg2_max = KVASER_USB_TSEG2_MAX,
> +	.sjw_max = KVASER_USB_SJW_MAX,
> +	.brp_min = KVASER_USB_BRP_MIN,
> +	.brp_max = KVASER_USB_BRP_MAX,
> +	.brp_inc = KVASER_USB_BRP_INC,
> +};
> +
> +static int kvaser_usb_set_bittiming(struct net_device *netdev)
> +{
> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> +	struct can_bittiming *bt = &priv->can.bittiming;
> +	struct kvaser_usb *dev = priv->dev;
> +	struct kvaser_msg msg;
> +
> +	msg.id = CMD_SET_BUS_PARAMS;
> +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_busparams);
> +	msg.u.busparams.channel = priv->channel;
> +	msg.u.busparams.tid = 0xff;
> +	msg.u.busparams.bitrate = bt->bitrate;

bitrate is le32

> +	msg.u.busparams.sjw = bt->sjw;
> +	msg.u.busparams.tseg1 = bt->prop_seg + bt->phase_seg1;
> +	msg.u.busparams.tseg2 = bt->phase_seg2;

C99 initializers, please

> +
> +	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
> +		msg.u.busparams.no_samp = 3;
> +	else
> +		msg.u.busparams.no_samp = 1;
> +
> +	return kvaser_usb_send_msg(dev, &msg);
> +}
> +
> +static int kvaser_usb_set_mode(struct net_device *netdev,
> +			       enum can_mode mode)
> +{
> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> +
> +	if (!priv->open_time)
> +		return -EINVAL;
> +
> +	switch (mode) {
> +	case CAN_MODE_START:
> +		if (netif_queue_stopped(netdev))
> +			netif_wake_queue(netdev);

No need to restart your USB device?

> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
> +static int kvaser_usb_get_berr_counter(const struct net_device *netdev,
> +				       struct can_berr_counter *bec)
> +{
> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> +
> +	bec->txerr = priv->bec.txerr;
> +	bec->rxerr = priv->bec.rxerr;
> +
> +	return 0;
> +}
> +
> +static int kvaser_usb_init_one(struct usb_interface *intf,
> +			       const struct usb_device_id *id, int channel)
> +{
> +	struct kvaser_usb *dev = usb_get_intfdata(intf);
> +	struct net_device *netdev;
> +	struct kvaser_usb_net_priv *priv;
> +	int i, err;
> +
> +	netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
> +	if (!netdev) {
> +		dev_err(&intf->dev, "Cannot alloc candev\n");
> +		return -ENOMEM;
> +	}
> +
> +	priv = netdev_priv(netdev);
> +
> +	init_usb_anchor(&priv->tx_submitted);
> +	atomic_set(&priv->active_tx_urbs, 0);
> +
> +	for (i = 0; i < MAX_TX_URBS; i++)
> +		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
> +
> +	priv->dev = dev;
> +	priv->netdev = netdev;
> +	priv->channel = channel;
> +
> +	priv->can.state = CAN_STATE_STOPPED;
> +	priv->can.clock.freq = CAN_USB_CLOCK;
> +	priv->can.bittiming_const = &kvaser_usb_bittiming_const;
> +	priv->can.do_set_bittiming = kvaser_usb_set_bittiming;
> +	priv->can.do_set_mode = kvaser_usb_set_mode;
> +	priv->can.do_get_berr_counter = kvaser_usb_get_berr_counter;
> +	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
> +	if (id->driver_info & KVASER_HAS_SILENT_MODE)
> +		priv->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
> +
> +	netdev->flags |= IFF_ECHO;
> +
> +	netdev->netdev_ops = &kvaser_usb_netdev_ops;
> +
> +	SET_NETDEV_DEV(netdev, &intf->dev);
> +
> +	err = register_candev(netdev);
> +	if (err) {
> +		dev_err(&intf->dev, "Failed to register can device\n");
> +		free_candev(netdev);
> +		return err;
> +	}
> +
> +	dev->nets[channel] = priv;
> +	netdev_info(netdev, "device %s registered\n", netdev->name);

netdev_info should take care of printing the device's name.
> +
> +	return 0;
> +}
> +
> +static int kvaser_usb_probe(struct usb_interface *intf,
> +			    const struct usb_device_id *id)
> +{
> +	struct kvaser_usb *dev;
> +	int err = -ENOMEM;
> +	int i;
> +
> +	dev = kzalloc(sizeof(*dev), GFP_KERNEL);

Who will free dev on driver unload? Please make use of devm_kzalloc().

> +	if (!dev)
> +		return -ENOMEM;
> +
> +	dev->udev = interface_to_usbdev(intf);
> +
> +	init_usb_anchor(&dev->rx_submitted);
> +
> +	usb_set_intfdata(intf, dev);
> +
> +	if (kvaser_usb_send_simple_msg(dev, CMD_RESET_CHIP, 0)) {
> +		dev_err(&intf->dev, "Cannot reset kvaser\n");
> +		goto error;
> +	}
> +
> +	if (kvaser_usb_get_software_info(dev)) {
> +		dev_err(&intf->dev, "Cannot get software infos\n");
> +		goto error;
> +	}
> +
> +	if (kvaser_usb_get_card_info(dev)) {
> +		dev_err(&intf->dev, "Cannot get card infos\n");
> +		goto error;
> +	}
> +
> +	dev_dbg(&intf->dev, "Firmware version: %d.%d.%d\n",
> +		 ((dev->fw_version >> 24) & 0xff),
> +		 ((dev->fw_version >> 16) & 0xff),
> +		 (dev->fw_version & 0xffff));
> +
> +	for (i = 0; i < dev->nchannels; i++)
> +		kvaser_usb_init_one(intf, id, i);
> +
> +	return 0;
> +
> +error:
> +	kfree(dev);
> +	return err;
> +}
> +
> +static void kvaser_usb_disconnect(struct usb_interface *intf)
> +{
> +	struct kvaser_usb *dev = usb_get_intfdata(intf);
> +	int i;
> +
> +	usb_set_intfdata(intf, NULL);
> +
> +	if (!dev)
> +		return;
> +
> +	for (i = 0; i < dev->nchannels; i++) {
> +		if (!dev->nets[i])
> +			continue;
> +
> +		unregister_netdev(dev->nets[i]->netdev);
> +		free_candev(dev->nets[i]->netdev);
> +	}
> +
> +	kvaser_usb_unlink_all_urbs(dev);
> +}
> +
> +static struct usb_driver kvaser_usb_driver = {
> +	.name = "kvaser_usb",
> +	.probe = kvaser_usb_probe,
> +	.disconnect = kvaser_usb_disconnect,
> +	.id_table = kvaser_usb_table
> +};
> +
> +module_usb_driver(kvaser_usb_driver);
> +
> +MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
> +MODULE_DESCRIPTION("Can driver for Kvaser CAN/USB devices");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/net/can/usb/kvaser_usb.h b/drivers/net/can/usb/kvaser_usb.h
> new file mode 100644
> index 0000000..8e0b6ab
> --- /dev/null
> +++ b/drivers/net/can/usb/kvaser_usb.h
> @@ -0,0 +1,237 @@
> +#ifndef _KVASER_USB_H_
> +#define _KVASER_USB_H_
> +
> +#define	MAX_TX_URBS			16
Please no tab between define and macro name
> +#define	MAX_RX_URBS			4
> +#define	START_TIMEOUT			1000
> +#define	STOP_TIMEOUT			1000
> +#define	USB_SEND_TIMEOUT		1000
> +#define	USB_RECEIVE_TIMEOUT		1000
> +#define	RX_BUFFER_SIZE			3072
> +#define	CAN_USB_CLOCK			8000000
> +#define	MAX_NET_DEVICES			3
> +
> +/* Kvaser USB devices */
> +#define	KVASER_VENDOR_ID		0x0bfd
> +#define	USB_LEAF_DEVEL_PRODUCT_ID	10
> +#define	USB_LEAF_LITE_PRODUCT_ID	11
> +#define	USB_LEAF_PRO_PRODUCT_ID		12
> +#define	USB_LEAF_SPRO_PRODUCT_ID	14
> +#define	USB_LEAF_PRO_LS_PRODUCT_ID	15
> +#define	USB_LEAF_PRO_SWC_PRODUCT_ID	16
> +#define	USB_LEAF_PRO_LIN_PRODUCT_ID	17
> +#define	USB_LEAF_SPRO_LS_PRODUCT_ID	18
> +#define	USB_LEAF_SPRO_SWC_PRODUCT_ID	19
> +#define	USB_MEMO2_DEVEL_PRODUCT_ID	22
> +#define	USB_MEMO2_HSHS_PRODUCT_ID	23
> +#define	USB_UPRO_HSHS_PRODUCT_ID	24
> +#define	USB_LEAF_LITE_GI_PRODUCT_ID	25
> +#define	USB_LEAF_PRO_OBDII_PRODUCT_ID	26
> +#define	USB_MEMO2_HSLS_PRODUCT_ID	27
> +#define	USB_LEAF_LITE_CH_PRODUCT_ID	28
> +#define	USB_BLACKBIRD_SPRO_PRODUCT_ID	29
> +#define	USB_OEM_MERCURY_PRODUCT_ID	34
> +#define	USB_OEM_LEAF_PRODUCT_ID		35
> +#define	USB_CAN_R_PRODUCT_ID		39
> +
> +/* USB devices features */
> +#define	KVASER_HAS_SILENT_MODE		(1 << 0)
pleae use BIT(0)
> +
> +/* Message header size */
> +#define	MSG_HEADER_LEN			2
> +
> +/* Can message flags */
> +#define	MSG_FLAG_ERROR_FRAME		(1 << 0)
> +#define	MSG_FLAG_OVERRUN		(1 << 1)
> +#define	MSG_FLAG_NERR			(1 << 2)
> +#define	MSG_FLAG_WAKEUP			(1 << 3)
> +#define	MSG_FLAG_REMOTE_FRAME		(1 << 4)
> +#define	MSG_FLAG_RESERVED		(1 << 5)
> +#define	MSG_FLAG_TX_ACK			(1 << 6)
> +#define	MSG_FLAG_TX_REQUEST		(1 << 7)
> +
> +/* Can states */
> +#define	M16C_STATE_BUS_RESET		(1 << 0)
> +#define	M16C_STATE_BUS_ERROR		(1 << 4)
> +#define	M16C_STATE_BUS_PASSIVE		(1 << 5)
> +#define	M16C_STATE_BUS_OFF		(1 << 6)
> +
> +/* Can msg ids */
> +#define	CMD_RX_STD_MESSAGE		12
> +#define	CMD_TX_STD_MESSAGE		13
> +#define	CMD_RX_EXT_MESSAGE		14
> +#define	CMD_TX_EXT_MESSAGE		15
> +#define	CMD_SET_BUS_PARAMS		16
> +#define	CMD_GET_BUS_PARAMS		17
> +#define	CMD_GET_BUS_PARAMS_REPLY	18
> +#define	CMD_GET_CHIP_STATE		19
> +#define	CMD_CHIP_STATE_EVENT		20
> +#define	CMD_SET_CTRL_MODE		21
> +#define	CMD_GET_CTRL_MODE		22
> +#define	CMD_GET_CTRL_MODE_REPLY		23
> +#define	CMD_RESET_CHIP			24
> +#define	CMD_RESET_CHIP_REPLY		25
> +#define	CMD_START_CHIP			26
> +#define	CMD_START_CHIP_REPLY		27
> +#define	CMD_STOP_CHIP			28
> +#define	CMD_STOP_CHIP_REPLY		29
> +#define	CMD_GET_CARD_INFO2		32
> +#define	CMD_GET_CARD_INFO		34
> +#define	CMD_GET_CARD_INFO_REPLY		35
> +#define	CMD_GET_SOFTWARE_INFO		38
> +#define	CMD_GET_SOFTWARE_INFO_REPLY	39
> +#define	CMD_ERROR_EVENT			45
> +#define	CMD_FLUSH_QUEUE			48
> +#define	CMD_TX_ACKNOWLEDGE		50
> +#define	CMD_CAN_ERROR_EVENT		51
> +#define	CMD_USB_THROTTLE		77
> +
> +/* error factors */
> +#define	M16C_EF_ACKE			(1 << 0)
> +#define	M16C_EF_CRCE			(1 << 1)
> +#define	M16C_EF_FORME			(1 << 2)
> +#define	M16C_EF_STFE			(1 << 3)
> +#define	M16C_EF_BITE0			(1 << 4)
> +#define	M16C_EF_BITE1			(1 << 5)
> +#define	M16C_EF_RCVE			(1 << 6)
> +#define	M16C_EF_TRE			(1 << 7)
> +
> +/* bittiming parameters */
> +#define	KVASER_USB_TSEG1_MIN		1
> +#define	KVASER_USB_TSEG1_MAX		16
> +#define	KVASER_USB_TSEG2_MIN		1
> +#define	KVASER_USB_TSEG2_MAX		8
> +#define	KVASER_USB_SJW_MAX		4
> +#define	KVASER_USB_BRP_MIN		1
> +#define	KVASER_USB_BRP_MAX		64
> +#define	KVASER_USB_BRP_INC		1
> +
> +/* ctrl modes */
> +#define	KVASER_CTRL_MODE_NORMAL		1
> +#define	KVASER_CTRL_MODE_SILENT		2
> +#define	KVASER_CTRL_MODE_SELFRECEPTION	3
> +#define	KVASER_CTRL_MODE_OFF		4
> +
> +struct kvaser_msg_simple {
> +	u8 tid;
> +	u8 channel;
> +} __packed;
> +
> +struct kvaser_msg_cardinfo {
> +	u8 tid;
> +	u8 nchannels;
> +	__le32 serial_number;
> +	__le32 padding;
> +	__le32 clock_resolution;
> +	__le32 mfgdate;
> +	u8 ean[8];
> +	u8 hw_revision;
> +	u8 usb_hs_mode;
> +	__le16 padding2;
> +} __packed;
> +
> +struct kvaser_msg_cardinfo2 {
> +	u8 tid;
> +	u8 channel;
> +	u8 pcb_id[24];
> +	__le32 oem_unlock_code;
> +} __packed;
> +
> +struct kvaser_msg_softinfo {
> +	u8 tid;
> +	u8 channel;
> +	__le32 sw_options;
> +	__le32 fw_version;
> +	__le16 max_outstanding_tx;
> +	__le16 padding[9];
> +} __packed;
> +
> +struct kvaser_msg_busparams {
> +	u8 tid;
> +	u8 channel;
> +	__le32 bitrate;
> +	u8 tseg1;
> +	u8 tseg2;
> +	u8 sjw;
> +	u8 no_samp;
> +} __packed;
> +
> +struct kvaser_msg_tx_can {
> +	u8 channel;
> +	u8 tid;
> +	u8 msg[14];
> +	u8 padding;
> +	u8 flags;
> +} __packed;
> +
> +struct kvaser_msg_rx_can {
> +	u8 channel;
> +	u8 flag;
> +	__le16 time[3];
> +	u8 msg[14];
> +} __packed;
> +
> +struct kvaser_msg_chip_state_event {
> +	u8 tid;
> +	u8 channel;
> +	__le16 time[3];
> +	u8 tx_errors_count;
> +	u8 rx_errors_count;
> +	u8 status;
> +	u8 padding[3];
> +} __packed;
> +
> +struct kvaser_msg_tx_acknowledge {
> +	u8 channel;
> +	u8 tid;
> +	__le16 time[3];
> +	u8 flags;
> +	u8 time_offset;
> +} __packed;
> +
> +struct kvaser_msg_error_event {
> +	u8 tid;
> +	u8 flags;
> +	__le16 time[3];
> +	u8 channel;
> +	u8 padding;
> +	u8 tx_errors_count;
> +	u8 rx_errors_count;
> +	u8 status;
> +	u8 error_factor;
> +} __packed;
> +
> +struct kvaser_msg_ctrl_mode {
> +	u8 tid;
> +	u8 channel;
> +	u8 ctrl_mode;
> +	u8 padding[3];
> +} __packed;
> +
> +struct kvaser_msg_flush_queue {
> +	u8 tid;
> +	u8 channel;
> +	u8 flags;
> +	u8 padding[3];
> +} __packed;
> +
> +struct kvaser_msg {
> +	u8 len;
> +	u8 id;
> +	union	{
> +		struct kvaser_msg_simple simple;
> +		struct kvaser_msg_cardinfo cardinfo;
> +		struct kvaser_msg_cardinfo2 cardinfo2;
> +		struct kvaser_msg_softinfo softinfo;
> +		struct kvaser_msg_busparams busparams;
> +		struct kvaser_msg_tx_can tx_can;
> +		struct kvaser_msg_rx_can rx_can;
> +		struct kvaser_msg_chip_state_event chip_state_event;
> +		struct kvaser_msg_tx_acknowledge tx_acknowledge;
> +		struct kvaser_msg_error_event error_event;
> +		struct kvaser_msg_ctrl_mode ctrl_mode;
> +		struct kvaser_msg_ctrl_mode flush_queue;
> +	} u;
> +} __packed;
> +
> +#endif
>

Hi Marc,

On Mon, Jul 30, 2012 at 01:11:46PM +0200, Marc Kleine-Budde wrote:
> On 07/30/2012 07:32 AM, Olivier Sobrie wrote:
> > This driver provides support for several Kvaser CAN/USB devices.
> > Such kind of devices supports up to three can network interfaces.
> > 
> > It has been tested with a Kvaser USB Leaf Light (one network interface)
> > connected to a pch_can interface.
> > The firmware version of the Kvaser device was 2.5.205.
> 
> Please add linux-usb@vger.kernel.org to Cc for review of the USB part.

Ok I'll do it when I send the new version of the patch.
But it might be a good idea to add an entry in the MAINTAINERS file so
that when someone sends a patch they are aware of this when the
get_maintainer script is invoked.

> Please combine .h and .c file. Please make use of netdev_LEVEL() for
> error printing, not dev_LEVEL().

I'll combine the .c and .h.
I used the netdev_LEVEL() everywhere it was possible. It requires to
have access to a pointer to netdev which is not always possible;
that's the reason why I used dev_LEVEL().

> 
> Please review if all members of the struct kvaser_msg are properly
> aligned. You never access the struct kvaser_msg_* members directly, as
> they are unaligned. Please check for le16 and le32 access. You missed to
> convert the bitrate.

Indeed. Thanks. I'll check if I didn't missed another one.

> 
> Please check if your driver survives hot-unplugging while sending and
> receiving CAN frames at maximum laod.

I tested this with two Kvaser sending frames with "cangen can0 -g 0 -i"
never saw a crash.

> 
> More comments inline,
> regards, Marc
> 
> > List of Kvaser devices supported by the driver:
> >   - Kvaser Leaf prototype (P010v2 and v3)
> >   - Kvaser Leaf Light (P010v3)
> >   - Kvaser Leaf Professional HS
> >   - Kvaser Leaf SemiPro HS
> >   - Kvaser Leaf Professional LS
> >   - Kvaser Leaf Professional SWC
> >   - Kvaser Leaf Professional LIN
> >   - Kvaser Leaf SemiPro LS
> >   - Kvaser Leaf SemiPro SWC
> >   - Kvaser Memorator II, Prototype
> >   - Kvaser Memorator II HS/HS
> >   - Kvaser USBcan Professional HS/HS
> >   - Kvaser Leaf Light GI
> >   - Kvaser Leaf Professional HS (OBD-II connector)
> >   - Kvaser Memorator Professional HS/LS
> >   - Kvaser Leaf Light "China"
> >   - Kvaser BlackBird SemiPro
> >   - Kvaser OEM Mercury
> >   - Kvaser OEM Leaf
> >   - Kvaser USBcan R
> > 
> > Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
> > ---
> >  drivers/net/can/usb/Kconfig      |   33 ++
> >  drivers/net/can/usb/Makefile     |    1 +
> >  drivers/net/can/usb/kvaser_usb.c | 1062 ++++++++++++++++++++++++++++++++++++++
> >  drivers/net/can/usb/kvaser_usb.h |  237 +++++++++
> >  4 files changed, 1333 insertions(+)
> >  create mode 100644 drivers/net/can/usb/kvaser_usb.c
> >  create mode 100644 drivers/net/can/usb/kvaser_usb.h
> > 
> > diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
> > index 0a68768..578955f 100644
> > --- a/drivers/net/can/usb/Kconfig
> > +++ b/drivers/net/can/usb/Kconfig
> > @@ -13,6 +13,39 @@ config CAN_ESD_USB2
> >            This driver supports the CAN-USB/2 interface
> >            from esd electronic system design gmbh (http://www.esd.eu).
> >  
> > +config CAN_KVASER_USB
> > +	tristate "Kvaser CAN/USB interface"
> > +	---help---
> > +	  This driver adds support for Kvaser CAN/USB devices like Kvaser
> > +	  Leaf Light.
> > +
> > +	  The driver gives support for the following devices:
> > +	    - Kvaser Leaf prototype (P010v2 and v3)
> > +	    - Kvaser Leaf Light (P010v3)
> > +	    - Kvaser Leaf Professional HS
> > +	    - Kvaser Leaf SemiPro HS
> > +	    - Kvaser Leaf Professional LS
> > +	    - Kvaser Leaf Professional SWC
> > +	    - Kvaser Leaf Professional LIN
> > +	    - Kvaser Leaf SemiPro LS
> > +	    - Kvaser Leaf SemiPro SWC
> > +	    - Kvaser Memorator II, Prototype
> > +	    - Kvaser Memorator II HS/HS
> > +	    - Kvaser USBcan Professional HS/HS
> > +	    - Kvaser Leaf Light GI
> > +	    - Kvaser Leaf Professional HS (OBD-II connector)
> > +	    - Kvaser Memorator Professional HS/LS
> > +	    - Kvaser Leaf Light "China"
> > +	    - Kvaser BlackBird SemiPro
> > +	    - Kvaser OEM Mercury
> > +	    - Kvaser OEM Leaf
> > +	    - Kvaser USBcan R
> > +
> > +	  If unsure, say N.
> > +
> > +	  To compile this driver as a module, choose M here: the
> > +	  module will be called kvaser_usb.
> > +
> >  config CAN_PEAK_USB
> >  	tristate "PEAK PCAN-USB/USB Pro interfaces"
> >  	---help---
> > diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
> > index da6d1d3..80a2ee4 100644
> > --- a/drivers/net/can/usb/Makefile
> > +++ b/drivers/net/can/usb/Makefile
> > @@ -4,6 +4,7 @@
> >  
> >  obj-$(CONFIG_CAN_EMS_USB) += ems_usb.o
> >  obj-$(CONFIG_CAN_ESD_USB2) += esd_usb2.o
> > +obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o
> >  obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
> >  
> >  ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
> > diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
> > new file mode 100644
> > index 0000000..4965480
> > --- /dev/null
> > +++ b/drivers/net/can/usb/kvaser_usb.c
> > @@ -0,0 +1,1062 @@
> > +/*
> 
> Please add a license statement and probably your copyright:
> 
>  * This program is free software; you can redistribute it and/or
>  * modify it under the terms of the GNU General Public License as
>  * published by the Free Software Foundation version 2.
> 
> You also should copy the copyright from the drivers you used:
> 
> > + * Parts of this driver are based on the following:
> > + *  - Kvaser linux leaf driver (version 4.78)
> 
> I just downloaded their driver and noticed that it's quite sparse on
> stating the license the code is released under.
> "doc/HTMLhelp/copyright.htx" is quite restrictive, the word GPL occurs 3
> times, all in MODULE_LICENSE("GPL"). Running modinfo on the usbcan.ko
> shows "license: GPL"

I'll add the license statement.
In fact it's the leaf.ko which is used for this device and it is under
GPL as modinfo said.

> 
> > + *  - CAN driver for esd CAN-USB/2
> > + */
> > +
> > +#include <linux/init.h>
> > +#include <linux/completion.h>
> > +#include <linux/module.h>
> > +#include <linux/netdevice.h>
> > +#include <linux/usb.h>
> > +
> > +#include <linux/can.h>
> > +#include <linux/can/dev.h>
> > +#include <linux/can/error.h>
> > +
> > +#include "kvaser_usb.h"
> > +
> > +struct kvaser_usb_tx_urb_context {
> > +	struct kvaser_usb_net_priv *priv;
> 
> Huh - how does this work without forward declaration?

It works.

"In C and C++ it is possible to declare pointers to structs before
declaring their struct layout, provided the pointers are not
dereferenced--this is known as forward declaration."

See http://www.linuxtopia.org/online_books/an_introduction_to_gcc/gccintro_94.html

> 
> > +	u32 echo_index;
> > +	int dlc;
> > +};
> > +
> > +struct kvaser_usb {
> > +	struct usb_device *udev;
> > +	struct kvaser_usb_net_priv *nets[MAX_NET_DEVICES];
> > +
> > +	struct usb_anchor rx_submitted;
> > +
> > +	u32 fw_version;
> > +	unsigned int nchannels;
> > +
> > +	bool rxinitdone;
> > +};
> > +
> > +struct kvaser_usb_net_priv {
> > +	struct can_priv can;
> > +
> > +	atomic_t active_tx_urbs;
> > +	struct usb_anchor tx_submitted;
> > +	struct kvaser_usb_tx_urb_context tx_contexts[MAX_TX_URBS];
> > +
> > +	int open_time;
> 
> please remove open_time

Ok.

> 
> > +	struct completion start_stop_comp;
> > +
> > +	struct kvaser_usb *dev;
> > +	struct net_device *netdev;
> > +	int channel;
> > +	struct can_berr_counter bec;
> > +};
> > +
> > +static struct usb_device_id kvaser_usb_table[] = {
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_DEVEL_PRODUCT_ID) },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_PRODUCT_ID) },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_PRODUCT_ID),
> > +		.driver_info = KVASER_HAS_SILENT_MODE },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_PRODUCT_ID),
> > +		.driver_info = KVASER_HAS_SILENT_MODE },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_LS_PRODUCT_ID),
> > +		.driver_info = KVASER_HAS_SILENT_MODE },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_SWC_PRODUCT_ID),
> > +		.driver_info = KVASER_HAS_SILENT_MODE },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_LIN_PRODUCT_ID),
> > +		.driver_info = KVASER_HAS_SILENT_MODE },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_LS_PRODUCT_ID),
> > +		.driver_info = KVASER_HAS_SILENT_MODE },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_SWC_PRODUCT_ID),
> > +		.driver_info = KVASER_HAS_SILENT_MODE },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_DEVEL_PRODUCT_ID),
> > +		.driver_info = KVASER_HAS_SILENT_MODE },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_HSHS_PRODUCT_ID),
> > +		.driver_info = KVASER_HAS_SILENT_MODE },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_UPRO_HSHS_PRODUCT_ID) },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_GI_PRODUCT_ID) },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_OBDII_PRODUCT_ID),
> > +		.driver_info = KVASER_HAS_SILENT_MODE },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_HSLS_PRODUCT_ID) },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_CH_PRODUCT_ID) },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_BLACKBIRD_SPRO_PRODUCT_ID) },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_OEM_MERCURY_PRODUCT_ID) },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_OEM_LEAF_PRODUCT_ID) },
> > +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_CAN_R_PRODUCT_ID) },
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(usb, kvaser_usb_table);
> > +
> > +static int kvaser_usb_send_msg(const struct kvaser_usb *dev,
> > +			       struct kvaser_msg *msg)
> inline?

Ok.

> > +{
> > +	int actual_len;
> > +
> > +	return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 1),
>                                                                   ^
> Can you please introduce a #define for this.

Ok. No problem.

> 
> > +			    msg, msg->len, &actual_len, USB_SEND_TIMEOUT);
> > +}
> > +
> > +static int kvaser_usb_wait_msg(const struct kvaser_usb *dev, u8 id,
> > +			       struct kvaser_msg *msg)
> > +{
> > +	struct kvaser_msg *tmp;
> > +	void *buf;
> > +	int actual_len;
> > +	int err;
> > +	int pos = 0;
> > +
> > +	buf = kzalloc(RX_BUFFER_SIZE, GFP_KERNEL);
> > +	if (!buf)
> > +		return -ENOMEM;
> > +
> > +	err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, 129),
>                                                                  ^^^
> dito

Ok too.

> 
> > +			   buf, RX_BUFFER_SIZE, &actual_len,
> > +			   USB_RECEIVE_TIMEOUT);
> > +	if (err < 0) {
> > +		kfree(buf);
> > +		return err;
> > +	}
> > +
> > +	while (pos < actual_len) {
> 
> Please check that pos + sizeof(*msg) is < actual_len, as you fill access
> it later.

I'll instead perform a check on 'pos + tmp->len < actual_len' and copy
only tmp->len instead of sizeof(*msg).
Thanks.

> 
> > +		tmp = buf + pos;
> > +
> > +		if (!tmp->len)
> > +			break;
> > +
> > +		if (tmp->id == id) {
> > +			memcpy(msg, tmp, sizeof(*msg));
> > +			kfree(buf);
> > +			return 0;
> > +		}
> > +
> > +		pos += tmp->len;
> > +	}
> > +
> > +	kfree(buf);
> > +
> > +	return -EINVAL;
> > +}
> > +
> > +static int kvaser_usb_send_simple_msg(const struct kvaser_usb *dev,
> > +				      u8 msg_id, int channel)
> > +{
> > +	struct kvaser_msg msg;
> > +	int err;
> > +
> > +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_simple);
> > +	msg.id = msg_id;
> > +	msg.u.simple.channel = channel;
> > +	msg.u.simple.tid = 0xff;
> 
> Please use C99 struct initializer.
> 
> struct kvaser_msg msg = {
> 	.len = ,
> 	.id =,
> };

Ok.

> 
> 
> > +
> > +	err = kvaser_usb_send_msg(dev, &msg);
> 
> 	just:
> 	return err;

Ok.

> 
> > +	if (err)
> > +		return err;
> > +
> > +	return 0;
> > +}
> > +
> > +static int kvaser_usb_get_software_info(struct kvaser_usb *dev)
> > +{
> > +	struct kvaser_msg msg;
> > +	int err;
> > +
> > +	err = kvaser_usb_send_simple_msg(dev, CMD_GET_SOFTWARE_INFO, 0);
> > +	if (err)
> > +		return err;
> > +
> > +	err = kvaser_usb_wait_msg(dev, CMD_GET_SOFTWARE_INFO_REPLY, &msg);
> > +	if (err)
> > +		return err;
> > +
> > +	dev->fw_version = le32_to_cpu(msg.u.softinfo.fw_version);
> > +
> > +	return 0;
> > +}
> > +
> > +static int kvaser_usb_get_card_info(struct kvaser_usb *dev)
> > +{
> > +	struct kvaser_msg msg;
> > +	int err;
> > +
> > +	err = kvaser_usb_send_simple_msg(dev, CMD_GET_CARD_INFO, 0);
> > +	if (err)
> > +		return err;
> > +
> > +	err = kvaser_usb_wait_msg(dev, CMD_GET_CARD_INFO_REPLY, &msg);
> > +	if (err)
> > +		return err;
> > +
> > +	dev->nchannels = msg.u.cardinfo.nchannels;
> > +
> > +	return 0;
> > +}
> > +
> > +static void kvaser_usb_tx_acknowledge(const struct kvaser_usb *dev,
> > +				      const struct kvaser_msg *msg)
> > +{
> > +	struct net_device_stats *stats;
> > +	struct kvaser_usb_tx_urb_context *context;
> > +	struct kvaser_usb_net_priv *priv;
> > +	u8 channel = msg->u.tx_acknowledge.channel;
> > +	u8 tid = msg->u.tx_acknowledge.tid;
> > +
> > +	if (channel >= dev->nchannels) {
> > +		dev_err(dev->udev->dev.parent,
> > +			"Invalid channel number (%d)\n", channel);
> > +		return;
> > +	}
> 
> can you do a check for (channel >= dev->nchannels), in a central place?
> e.g. kvaser_usb_handle_message()?

The problem is that channel is not always at the same place in the
messages I get from the hardware. 'tid' and 'channel' are inverted for
tx and rx frames.
e.g.

struct kvaser_msg_tx_can {
        u8 channel;
        u8 tid;
        u8 msg[14];
        u8 padding;
        u8 flags;
} __packed;

struct kvaser_msg_busparams {
        u8 tid;
        u8 channel;
        __le32 bitrate;
        u8 tseg1;
        u8 tseg2;
        u8 sjw;
        u8 no_samp;
} __packed;

> 
> > +
> > +	priv = dev->nets[channel];
> > +
> > +	if (!netif_device_present(priv->netdev))
> > +		return;
> > +
> > +	stats = &priv->netdev->stats;
> > +
> > +	context = &priv->tx_contexts[tid % MAX_TX_URBS];
> > +
> > +	/*
> > +	 * It looks like the firmware never sets the flags field of the
> > +	 * tx_acknowledge frame and never reports a transmit failure.
> > +	 * If the can message can't be transmited (e.g. incompatible
> > +	 * bitrates), a frame CMD_CAN_ERROR_EVENT is sent (with a null
> > +	 * tid) and the firmware tries to transmit again the packet until
> > +	 * it succeeds. Once the packet is successfully transmitted, then
> > +	 * the tx_acknowledge frame is sent.
> > +	 */
> > +
> > +	stats->tx_packets++;
> > +	stats->tx_bytes += context->dlc;
> > +	can_get_echo_skb(priv->netdev, context->echo_index);
> > +
> > +	context->echo_index = MAX_TX_URBS;
> > +	atomic_dec(&priv->active_tx_urbs);
> > +
> > +	netif_wake_queue(priv->netdev);
> > +}
> > +
> > +static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
> > +				const struct kvaser_msg *msg)
> > +{
> > +	struct can_frame *cf;
> > +	struct sk_buff *skb;
> > +	struct net_device_stats *stats;
> > +	struct kvaser_usb_net_priv *priv;
> > +	u8 channel, status, txerr, rxerr;
> > +
> > +	if (msg->id == CMD_CAN_ERROR_EVENT) {
> > +		channel = msg->u.error_event.channel;
> > +		status =  msg->u.error_event.status;
> > +		txerr = msg->u.error_event.tx_errors_count;
> > +		rxerr = msg->u.error_event.rx_errors_count;
> > +	} else {
> > +		channel = msg->u.chip_state_event.channel;
> > +		status =  msg->u.chip_state_event.status;
> > +		txerr = msg->u.chip_state_event.tx_errors_count;
> > +		rxerr = msg->u.chip_state_event.rx_errors_count;
> > +	}
> > +
> > +	if (channel >= dev->nchannels) {
> > +		dev_err(dev->udev->dev.parent,
> > +			"Invalid channel number (%d)\n", channel);
> > +		return;
> > +	}
> > +
> > +	priv = dev->nets[channel];
> > +	stats = &priv->netdev->stats;
> > +
> > +	skb = alloc_can_err_skb(priv->netdev, &cf);
> > +	if (!skb) {
> > +		stats->rx_dropped++;
> > +		return;
> > +	}
> > +
> > +	if ((status & M16C_STATE_BUS_OFF) ||
> > +	    (status & M16C_STATE_BUS_RESET)) {
> > +		priv->can.state = CAN_STATE_BUS_OFF;
> > +		cf->can_id |= CAN_ERR_BUSOFF;
> > +		can_bus_off(priv->netdev);
> > +	} else if (status & M16C_STATE_BUS_ERROR) {
> > +		priv->can.state = CAN_STATE_ERROR_WARNING;
> > +		priv->can.can_stats.error_warning++;
> > +	} else if (status & M16C_STATE_BUS_PASSIVE) {
> > +		priv->can.state = CAN_STATE_ERROR_PASSIVE;
> > +		priv->can.can_stats.error_passive++;
> > +	} else {
> > +		priv->can.state = CAN_STATE_ERROR_ACTIVE;
> > +		cf->can_id |= CAN_ERR_PROT;
> > +		cf->data[2] = CAN_ERR_PROT_ACTIVE;
> > +	}
> > +
> > +	if (msg->id == CMD_CAN_ERROR_EVENT) {
> > +		u8 error_factor = msg->u.error_event.error_factor;
> > +
> > +		priv->can.can_stats.bus_error++;
> > +		stats->rx_errors++;
> > +
> > +		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
> > +
> > +		if ((priv->can.state == CAN_STATE_ERROR_WARNING) ||
> > +		    (priv->can.state == CAN_STATE_ERROR_PASSIVE)) {
> > +			cf->data[1] = (txerr > rxerr) ?
> > +				CAN_ERR_CRTL_TX_PASSIVE
> > +				: CAN_ERR_CRTL_RX_PASSIVE;
> > +		}
> > +
> > +		if (error_factor & M16C_EF_ACKE)
> > +			cf->data[3] |= (CAN_ERR_PROT_LOC_ACK |
> > +					CAN_ERR_PROT_LOC_ACK_DEL);
> > +		if (error_factor & M16C_EF_CRCE)
> > +			cf->data[3] |= (CAN_ERR_PROT_LOC_CRC_SEQ |
> > +					CAN_ERR_PROT_LOC_CRC_DEL);
> > +		if (error_factor & M16C_EF_FORME)
> > +			cf->data[2] |= CAN_ERR_PROT_FORM;
> > +		if (error_factor & M16C_EF_STFE)
> > +			cf->data[2] |= CAN_ERR_PROT_STUFF;
> > +		if (error_factor & M16C_EF_BITE0)
> > +			cf->data[2] |= CAN_ERR_PROT_BIT0;
> > +		if (error_factor & M16C_EF_BITE1)
> > +			cf->data[2] |= CAN_ERR_PROT_BIT1;
> > +		if (error_factor & M16C_EF_TRE)
> > +			cf->data[2] |= CAN_ERR_PROT_TX;
> > +	}
> > +
> > +	cf->data[6] = txerr;
> > +	cf->data[7] = rxerr;
> > +
> > +	netif_rx(skb);
> > +
> > +	priv->bec.txerr = txerr;
> > +	priv->bec.rxerr = rxerr;
> > +
> > +	stats->rx_packets++;
> > +	stats->rx_bytes += cf->can_dlc;
> > +}
> > +
> > +static void kvaser_usb_rx_can_msg(const struct kvaser_usb *dev,
> > +				  const struct kvaser_msg *msg)
> > +{
> > +	struct kvaser_usb_net_priv *priv;
> > +	struct can_frame *cf;
> > +	struct sk_buff *skb;
> > +	struct net_device_stats *stats;
> > +	u8 channel = msg->u.rx_can.channel;
> > +
> > +	if (channel >= dev->nchannels) {
> > +		dev_err(dev->udev->dev.parent,
> > +			"Invalid channel number (%d)\n", channel);
> > +		return;
> > +	}
> > +
> > +	priv = dev->nets[channel];
> > +	stats = &priv->netdev->stats;
> > +
> > +	skb = alloc_can_skb(priv->netdev, &cf);
> > +	if (skb == NULL) {
> > +		stats->tx_dropped++;
> > +		return;
> > +	}
> > +
> > +	cf->can_id = ((msg->u.rx_can.msg[0] & 0x1f) << 6) |
> > +		     (msg->u.rx_can.msg[1] & 0x3f);
> > +	cf->can_dlc = get_can_dlc(msg->u.rx_can.msg[5]);
> > +
> > +	if (msg->id == CMD_RX_EXT_MESSAGE) {
> > +		cf->can_id <<= 18;
> > +		cf->can_id += ((msg->u.rx_can.msg[2] & 0x0f) << 14) |
>                            |=
> 
> is more appropriate here

Ok.

> 
> > +			      ((msg->u.rx_can.msg[3] & 0xff) << 6) |
> > +			      (msg->u.rx_can.msg[4] & 0x3f);
> > +		cf->can_id |= CAN_EFF_FLAG;
> > +	}
> > +
> > +	if (msg->u.rx_can.flag & MSG_FLAG_REMOTE_FRAME) {
> > +		cf->can_id |= CAN_RTR_FLAG;
> > +	} else if (msg->u.rx_can.flag & (MSG_FLAG_ERROR_FRAME |
> > +						MSG_FLAG_NERR)) {
> > +		cf->can_id |= CAN_ERR_FLAG;
> > +		cf->can_dlc = CAN_ERR_DLC;
> 
> What kind of error is this? Can you set cf->data? What about the
> original cd->can_id? What about the stats->rx_*error* stats?

Good question I've to take a look to this.

> 
> > +	} else if (msg->u.rx_can.flag & MSG_FLAG_OVERRUN) {
> > +		cf->can_id = CAN_ERR_FLAG | CAN_ERR_CRTL;
> > +		cf->can_dlc = CAN_ERR_DLC;
> > +		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
> > +
> > +		stats->rx_over_errors++;
> > +		stats->rx_errors++;
> > +	} else if (!msg->u.rx_can.flag) {
> > +		memcpy(cf->data, &msg->u.rx_can.msg[6], cf->can_dlc);
> > +	} else {
> > +		kfree_skb(skb);
> > +		return;
> > +	}
> > +
> > +	netif_rx(skb);
> > +
> > +	stats->rx_packets++;
> > +	stats->rx_bytes += cf->can_dlc;
> > +}
> > +
> > +static void kvaser_usb_start_stop_chip_reply(const struct kvaser_usb *dev,
> > +					     const struct kvaser_msg *msg)
> > +{
> > +	struct kvaser_usb_net_priv *priv;
> > +	u8 channel = msg->u.simple.channel;
> > +
> > +	if (channel >= dev->nchannels) {
> > +		dev_err(dev->udev->dev.parent,
> > +			"Invalid channel number (%d)\n", channel);
> > +		return;
> > +	}
> > +
> > +	priv = dev->nets[channel];
> > +
> > +	complete(&priv->start_stop_comp);
> > +}
> > +
> > +static void kvaser_usb_handle_message(const struct kvaser_usb *dev,
> > +				      const struct kvaser_msg *msg)
> > +{
> > +	switch (msg->id) {
> > +	case CMD_START_CHIP_REPLY:
> > +	case CMD_STOP_CHIP_REPLY:
> > +		kvaser_usb_start_stop_chip_reply(dev, msg);
> > +		break;
> > +
> > +	case CMD_RX_STD_MESSAGE:
> > +	case CMD_RX_EXT_MESSAGE:
> > +		kvaser_usb_rx_can_msg(dev, msg);
> > +		break;
> > +
> > +	case CMD_CHIP_STATE_EVENT:
> > +	case CMD_CAN_ERROR_EVENT:
> > +		kvaser_usb_rx_error(dev, msg);
> > +		break;
> > +
> > +	case CMD_TX_ACKNOWLEDGE:
> > +		kvaser_usb_tx_acknowledge(dev, msg);
> > +		break;
> > +
> > +	default:
> > +		dev_warn(dev->udev->dev.parent,
> > +			 "Unhandled message (%d)\n", msg->id);
> > +		break;
> > +	}
> > +}
> > +
> > +static void kvaser_usb_read_bulk_callback(struct urb *urb)
> > +{
> > +	struct kvaser_usb *dev = urb->context;
> > +	struct kvaser_msg *msg;
> > +	int pos = 0;
> > +	int err, i;
> > +
> > +	switch (urb->status) {
> > +	case 0:
> > +		break;
> > +	case -ENOENT:
> > +	case -ESHUTDOWN:
> > +		return;
> > +	default:
> > +		dev_info(dev->udev->dev.parent, "Rx URB aborted (%d)\n",
> > +			 urb->status);
> > +		goto resubmit_urb;
> > +	}
> > +
> > +	while (pos < urb->actual_length) {
> 
> please check here for pos + sizeof(*msg), too

Same as above.

> 
> > +		msg = urb->transfer_buffer + pos;
> > +
> > +		if (!msg->len)
> > +			break;
> > +
> > +		kvaser_usb_handle_message(dev, msg);
> > +
> > +		if (pos > urb->actual_length) {
> > +			dev_err(dev->udev->dev.parent, "Format error\n");
> > +			break;
> > +		}
> > +
> > +		pos += msg->len;
> > +	}
> > +
> > +resubmit_urb:
> > +	usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 129),
>                                                                      ^^^
> 
> use #define

Ok.

> 
> > +			  urb->transfer_buffer, RX_BUFFER_SIZE,
> > +			  kvaser_usb_read_bulk_callback, dev);
> > +
> > +	err = usb_submit_urb(urb, GFP_ATOMIC);
> > +	if (err == -ENODEV) {
> > +		for (i = 0; i < dev->nchannels; i++) {
> > +			if (!dev->nets[i])
> > +				continue;
> > +
> > +			netif_device_detach(dev->nets[i]->netdev);
> > +		}
> > +	} else if (err) {
> > +		dev_err(dev->udev->dev.parent,
> > +			"Failed resubmitting read bulk urb: %d\n", err);
> > +	}
> > +
> > +	return;
> > +}
> > +
> > +static int kvaser_usb_setup_rx_urbs(struct kvaser_usb *dev)
> > +{
> > +	int i, err = 0;
> > +
> > +	if (dev->rxinitdone)
> > +		return 0;
> > +
> > +	for (i = 0; i < MAX_RX_URBS; i++) {
> > +		struct urb *urb = NULL;
> > +		u8 *buf = NULL;
> > +
> > +		urb = usb_alloc_urb(0, GFP_KERNEL);
> > +		if (!urb) {
> > +			dev_warn(dev->udev->dev.parent,
> > +				 "No memory left for URBs\n");
> > +			err = -ENOMEM;
> > +			break;
> > +		}
> > +
> > +		buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE,
> > +					 GFP_KERNEL, &urb->transfer_dma);
> > +		if (!buf) {
> > +			dev_warn(dev->udev->dev.parent,
> > +				 "No memory left for USB buffer\n");
> > +			usb_free_urb(urb);
> > +			err = -ENOMEM;
> > +			break;
> > +		}
> > +
> > +		usb_fill_bulk_urb(urb, dev->udev,
> > +				  usb_rcvbulkpipe(dev->udev, 129),
> 
> use #define

Ok.

> 
> > +				  buf, RX_BUFFER_SIZE,
> > +				  kvaser_usb_read_bulk_callback, dev);
> > +		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> > +		usb_anchor_urb(urb, &dev->rx_submitted);
> > +
> > +		err = usb_submit_urb(urb, GFP_KERNEL);
> > +		if (err) {
> > +			usb_unanchor_urb(urb);
> > +			usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
> > +					  urb->transfer_dma);
> > +			break;
> > +		}
> > +
> > +		usb_free_urb(urb);
> > +	}
> > +
> > +	if (i == 0) {
> > +		dev_warn(dev->udev->dev.parent,
> > +			 "Cannot setup read URBs, error %d\n", err);
> > +		return err;
> > +	} else if (i < MAX_RX_URBS) {
> > +		dev_warn(dev->udev->dev.parent,
> > +			 "RX performances may be slow\n");
> > +	}
> > +
> > +	dev->rxinitdone = true;
> > +
> > +	return 0;
> > +}
> > +
> > +static int kvaser_usb_set_opt_mode(const struct kvaser_usb_net_priv *priv)
> > +{
> > +	struct kvaser_msg msg;
> > +
> > +	memset(&msg, 0x00, sizeof(msg));
> > +	msg.id = CMD_SET_CTRL_MODE;
> > +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_ctrl_mode);
> > +	msg.u.ctrl_mode.tid = 0xff;
> > +	msg.u.ctrl_mode.channel = priv->channel;
> 
> please use C99 struct initializers

Ok.

> 
> > +
> > +	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
> > +		msg.u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_SILENT;
> > +	else
> > +		msg.u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_NORMAL;
> > +
> > +	return kvaser_usb_send_msg(priv->dev, &msg);
> > +}
> > +
> > +static int kvaser_usb_start_chip(struct kvaser_usb_net_priv *priv)
> > +{
> > +	int err;
> > +
> > +	init_completion(&priv->start_stop_comp);
> > +
> > +	err = kvaser_usb_send_simple_msg(priv->dev, CMD_START_CHIP,
> > +					 priv->channel);
> > +	if (err)
> > +		return err;
> > +
> > +	if (!wait_for_completion_timeout(&priv->start_stop_comp,
> > +					 msecs_to_jiffies(START_TIMEOUT)))
> > +		return -ETIMEDOUT;
> > +
> > +	return 0;
> > +}
> > +
> > +static int kvaser_usb_open(struct net_device *netdev)
> > +{
> > +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> > +	struct kvaser_usb *dev = priv->dev;
> > +	int err;
> > +
> > +	err = open_candev(netdev);
> > +	if (err)
> > +		return err;
> > +
> > +	err = kvaser_usb_setup_rx_urbs(dev);
> > +	if (err)
> > +		return err;
> > +
> > +	err = kvaser_usb_set_opt_mode(priv);
> > +	if (err)
> > +		return err;
> > +
> > +	err = kvaser_usb_start_chip(priv);
> > +	if (err) {
> > +		netdev_warn(netdev, "Cannot start device, error %d\n", err);
> > +		close_candev(netdev);
> > +		return err;
> > +	}
> > +
> > +	priv->can.state = CAN_STATE_ERROR_ACTIVE;
> > +	priv->open_time = jiffies;
> > +	netif_start_queue(netdev);
> > +
> > +	return 0;
> > +}
> > +
> > +static void kvaser_usb_unlink_tx_urbs(struct kvaser_usb_net_priv *priv)
> > +{
> > +	int i;
> > +
> > +	usb_kill_anchored_urbs(&priv->tx_submitted);
> > +	atomic_set(&priv->active_tx_urbs, 0);
> > +
> > +	for (i = 0; i < MAX_TX_URBS; i++)
> ARRAY_SIZE(priv->tx_contexts) instead of MAX_TX_URBS

Ok.

> > +		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
> > +}
> > +
> > +static void kvaser_usb_unlink_all_urbs(struct kvaser_usb *dev)
> > +{
> > +	int i;
> > +
> > +	usb_kill_anchored_urbs(&dev->rx_submitted);
> > +
> > +	for (i = 0; i < MAX_NET_DEVICES; i++) {
> ARRAY_SIZE()
> > +		struct kvaser_usb_net_priv *priv = dev->nets[i];
> > +
> > +		if (priv)
> > +			kvaser_usb_unlink_tx_urbs(priv);
> > +	}
> > +}
> > +
> > +static int kvaser_usb_stop_chip(struct kvaser_usb_net_priv *priv)
> > +{
> > +	int err;
> > +
> > +	init_completion(&priv->start_stop_comp);
> > +
> > +	err = kvaser_usb_send_simple_msg(priv->dev, CMD_STOP_CHIP,
> > +					 priv->channel);
> > +	if (err)
> > +		return err;
> > +
> > +	if (!wait_for_completion_timeout(&priv->start_stop_comp,
> > +					 msecs_to_jiffies(STOP_TIMEOUT)))
> > +		return -ETIMEDOUT;
> > +
> > +	return 0;
> > +}
> > +
> > +static int kvaser_usb_flush_queue(struct kvaser_usb_net_priv *priv)
> > +{
> > +	struct kvaser_msg msg;
> > +
> > +	memset(&msg, 0x00, sizeof(msg));
> > +	msg.id = CMD_FLUSH_QUEUE;
> > +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_flush_queue);
> > +	msg.u.flush_queue.channel = priv->channel;
> C99 initialziers, please

Ok.

> > +
> > +	return kvaser_usb_send_msg(priv->dev, &msg);
> > +}
> > +
> > +static int kvaser_usb_close(struct net_device *netdev)
> > +{
> > +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> > +	int err;
> > +
> > +	netif_stop_queue(netdev);
> > +
> > +	err = kvaser_usb_flush_queue(priv);
> > +	if (err)
> > +		netdev_warn(netdev, "Cannot flush queue, error %d\n", err);
> > +
> > +	err = kvaser_usb_stop_chip(priv);
> > +	if (err) {
> > +		netdev_warn(netdev, "Cannot stop device, error %d\n", err);
> > +		return err;
> > +	}
> > +
> > +	kvaser_usb_unlink_tx_urbs(priv);
> > +
> > +	priv->can.state = CAN_STATE_STOPPED;
> > +	close_candev(priv->netdev);
> > +	priv->open_time = 0;
> > +
> > +	return 0;
> > +}
> > +
> > +static void kvaser_usb_write_bulk_callback(struct urb *urb)
> > +{
> > +	struct kvaser_usb_tx_urb_context *context = urb->context;
> > +	struct kvaser_usb_net_priv *priv;
> > +	struct net_device *netdev;
> > +
> > +	if (WARN_ON(!context))
> > +		return;
> > +
> > +	priv = context->priv;
> > +	netdev = priv->netdev;
> > +
> > +	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
> > +			  urb->transfer_buffer, urb->transfer_dma);
> > +
> > +	if (!netif_device_present(netdev))
> > +		return;
> > +
> > +	if (urb->status)
> > +		netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
> > +
> > +	netdev->trans_start = jiffies;
> 
> Is trans_start needed? at least for non-usb devices it works without.

I don't know, I'll try to figure this out.
I see it's used in the two others CAN/USB drivers, 'ems_usb.c' and
'esd_usb2.c'

> 
> > +}
> > +
> > +static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
> > +					 struct net_device *netdev)
> > +{
> > +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> > +	struct kvaser_usb *dev = priv->dev;
> > +	struct net_device_stats *stats = &netdev->stats;
> > +	struct can_frame *cf = (struct can_frame *)skb->data;
> > +	struct kvaser_usb_tx_urb_context *context = NULL;
> > +	struct urb *urb;
> > +	void *buf;
> > +	struct kvaser_msg *msg;
> > +	int i, err;
> > +	int ret = NETDEV_TX_OK;
> > +
> > +	if (can_dropped_invalid_skb(netdev, skb))
> > +		return NETDEV_TX_OK;
> > +
> > +	urb = usb_alloc_urb(0, GFP_ATOMIC);
> > +	if (!urb) {
> > +		netdev_err(netdev, "No memory left for URBs\n");
> > +		stats->tx_dropped++;
> > +		dev_kfree_skb(skb);
> > +		goto nourbmem;
> > +	}
> > +
> > +	buf = usb_alloc_coherent(dev->udev, sizeof(struct kvaser_msg),
> > +				 GFP_ATOMIC, &urb->transfer_dma);
> > +	if (!buf) {
> > +		netdev_err(netdev, "No memory left for USB buffer\n");
> > +		stats->tx_dropped++;
> > +		dev_kfree_skb(skb);
> > +		goto nobufmem;
> > +	}
> > +
> > +	msg = (struct kvaser_msg *)buf;
> > +	msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_tx_can);
> > +	msg->u.tx_can.flags = 0;
> > +	msg->u.tx_can.channel = priv->channel;
> > +
> > +	if (cf->can_id & CAN_EFF_FLAG) {
> > +		msg->id = CMD_TX_EXT_MESSAGE;
> > +		msg->u.tx_can.msg[0] = (cf->can_id >> 24) & 0x1f;
> > +		msg->u.tx_can.msg[1] = (cf->can_id >> 18) & 0x3f;
> > +		msg->u.tx_can.msg[2] = (cf->can_id >> 14) & 0x0f;
> > +		msg->u.tx_can.msg[3] = (cf->can_id >> 6) & 0xff;
> > +		msg->u.tx_can.msg[4] = cf->can_id & 0x3f;
> > +	} else {
> > +		msg->id = CMD_TX_STD_MESSAGE;
> > +		msg->u.tx_can.msg[0] = (cf->can_id >> 6) & 0x1f;
> > +		msg->u.tx_can.msg[1] = cf->can_id & 0x3f;
> > +	}
> > +
> > +	msg->u.tx_can.msg[5] = cf->can_dlc;
> > +	memcpy(&msg->u.tx_can.msg[6], cf->data, cf->can_dlc);
> > +
> > +	if (cf->can_id & CAN_RTR_FLAG)
> > +		msg->u.tx_can.flags |= MSG_FLAG_REMOTE_FRAME;
> > +
> > +	for (i = 0; i < MAX_TX_URBS; i++) {
> ARRAY_SIZE

Ok.

> > +		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
> > +			context = &priv->tx_contexts[i];
> > +			break;
> > +		}
> > +	}
> > +
> > +	if (!context) {
> > +		netdev_warn(netdev, "cannot find free context\n");
> > +		ret =  NETDEV_TX_BUSY;
> > +		goto releasebuf;
> > +	}
> > +
> > +	context->priv = priv;
> > +	context->echo_index = i;
> > +	context->dlc = cf->can_dlc;
> > +
> > +	msg->u.tx_can.tid = context->echo_index;
> > +
> > +	usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
> > +			  buf, msg->len,
> > +			  kvaser_usb_write_bulk_callback, context);
> > +	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> > +	usb_anchor_urb(urb, &priv->tx_submitted);
> > +
> > +	can_put_echo_skb(skb, netdev, context->echo_index);
> > +
> > +	atomic_inc(&priv->active_tx_urbs);
> > +
> > +	if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
> > +		netif_stop_queue(netdev);
> > +
> > +	err = usb_submit_urb(urb, GFP_ATOMIC);
> > +	if (unlikely(err)) {
> > +		can_free_echo_skb(netdev, context->echo_index);
> > +
> > +		atomic_dec(&priv->active_tx_urbs);
> > +		usb_unanchor_urb(urb);
> > +
> > +		stats->tx_dropped++;
> > +
> > +		if (err == -ENODEV)
> > +			netif_device_detach(netdev);
> > +		else
> > +			netdev_warn(netdev, "Failed tx_urb %d\n", err);
> > +
> > +		goto releasebuf;
> > +	}
> > +
> > +	netdev->trans_start = jiffies;
> > +
> > +	usb_free_urb(urb);
> > +
> > +	return NETDEV_TX_OK;
> > +
> > +releasebuf:
> > +	usb_free_coherent(dev->udev, sizeof(struct kvaser_msg),
> > +			  buf, urb->transfer_dma);
> > +nobufmem:
> > +	usb_free_urb(urb);
> > +nourbmem:
> > +	return ret;
> > +}
> > +
> > +static const struct net_device_ops kvaser_usb_netdev_ops = {
> > +	.ndo_open = kvaser_usb_open,
> > +	.ndo_stop = kvaser_usb_close,
> > +	.ndo_start_xmit = kvaser_usb_start_xmit,
> > +};
> > +
> > +static struct can_bittiming_const kvaser_usb_bittiming_const = {
> > +	.name = "kvaser_usb",
> > +	.tseg1_min = KVASER_USB_TSEG1_MIN,
> > +	.tseg1_max = KVASER_USB_TSEG1_MAX,
> > +	.tseg2_min = KVASER_USB_TSEG2_MIN,
> > +	.tseg2_max = KVASER_USB_TSEG2_MAX,
> > +	.sjw_max = KVASER_USB_SJW_MAX,
> > +	.brp_min = KVASER_USB_BRP_MIN,
> > +	.brp_max = KVASER_USB_BRP_MAX,
> > +	.brp_inc = KVASER_USB_BRP_INC,
> > +};
> > +
> > +static int kvaser_usb_set_bittiming(struct net_device *netdev)
> > +{
> > +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> > +	struct can_bittiming *bt = &priv->can.bittiming;
> > +	struct kvaser_usb *dev = priv->dev;
> > +	struct kvaser_msg msg;
> > +
> > +	msg.id = CMD_SET_BUS_PARAMS;
> > +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_busparams);
> > +	msg.u.busparams.channel = priv->channel;
> > +	msg.u.busparams.tid = 0xff;
> > +	msg.u.busparams.bitrate = bt->bitrate;
> 
> bitrate is le32

Indeed ! I'll fix this.

> 
> > +	msg.u.busparams.sjw = bt->sjw;
> > +	msg.u.busparams.tseg1 = bt->prop_seg + bt->phase_seg1;
> > +	msg.u.busparams.tseg2 = bt->phase_seg2;
> 
> C99 initializers, please
> 
> > +
> > +	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
> > +		msg.u.busparams.no_samp = 3;
> > +	else
> > +		msg.u.busparams.no_samp = 1;
> > +
> > +	return kvaser_usb_send_msg(dev, &msg);
> > +}
> > +
> > +static int kvaser_usb_set_mode(struct net_device *netdev,
> > +			       enum can_mode mode)
> > +{
> > +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> > +
> > +	if (!priv->open_time)
> > +		return -EINVAL;
> > +
> > +	switch (mode) {
> > +	case CAN_MODE_START:
> > +		if (netif_queue_stopped(netdev))
> > +			netif_wake_queue(netdev);
> 
> No need to restart your USB device?

No. I don't think so.
The module continuously tries to transmit the frame and isn't stopped.
So there is no need to restart it if it has been explicitely stopped.

When it cannot transmit, the module try again and sends continuously
CMD_CAN_ERROR_EVENT frames until it succeeds to transmit the frame.
If the device is stopped with the command CMD_STOP_CHIP then it stops
sending these CMD_CAN_ERROR_EVENT.
Should I handle this in another manner?

> 
> > +		break;
> > +	default:
> > +		return -EOPNOTSUPP;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int kvaser_usb_get_berr_counter(const struct net_device *netdev,
> > +				       struct can_berr_counter *bec)
> > +{
> > +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> > +
> > +	bec->txerr = priv->bec.txerr;
> > +	bec->rxerr = priv->bec.rxerr;
> > +
> > +	return 0;
> > +}
> > +
> > +static int kvaser_usb_init_one(struct usb_interface *intf,
> > +			       const struct usb_device_id *id, int channel)
> > +{
> > +	struct kvaser_usb *dev = usb_get_intfdata(intf);
> > +	struct net_device *netdev;
> > +	struct kvaser_usb_net_priv *priv;
> > +	int i, err;
> > +
> > +	netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
> > +	if (!netdev) {
> > +		dev_err(&intf->dev, "Cannot alloc candev\n");
> > +		return -ENOMEM;
> > +	}
> > +
> > +	priv = netdev_priv(netdev);
> > +
> > +	init_usb_anchor(&priv->tx_submitted);
> > +	atomic_set(&priv->active_tx_urbs, 0);
> > +
> > +	for (i = 0; i < MAX_TX_URBS; i++)
> > +		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
> > +
> > +	priv->dev = dev;
> > +	priv->netdev = netdev;
> > +	priv->channel = channel;
> > +
> > +	priv->can.state = CAN_STATE_STOPPED;
> > +	priv->can.clock.freq = CAN_USB_CLOCK;
> > +	priv->can.bittiming_const = &kvaser_usb_bittiming_const;
> > +	priv->can.do_set_bittiming = kvaser_usb_set_bittiming;
> > +	priv->can.do_set_mode = kvaser_usb_set_mode;
> > +	priv->can.do_get_berr_counter = kvaser_usb_get_berr_counter;
> > +	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
> > +	if (id->driver_info & KVASER_HAS_SILENT_MODE)
> > +		priv->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
> > +
> > +	netdev->flags |= IFF_ECHO;
> > +
> > +	netdev->netdev_ops = &kvaser_usb_netdev_ops;
> > +
> > +	SET_NETDEV_DEV(netdev, &intf->dev);
> > +
> > +	err = register_candev(netdev);
> > +	if (err) {
> > +		dev_err(&intf->dev, "Failed to register can device\n");
> > +		free_candev(netdev);
> > +		return err;
> > +	}
> > +
> > +	dev->nets[channel] = priv;
> > +	netdev_info(netdev, "device %s registered\n", netdev->name);
> 
> netdev_info should take care of printing the device's name.

Ok.

> > +
> > +	return 0;
> > +}
> > +
> > +static int kvaser_usb_probe(struct usb_interface *intf,
> > +			    const struct usb_device_id *id)
> > +{
> > +	struct kvaser_usb *dev;
> > +	int err = -ENOMEM;
> > +	int i;
> > +
> > +	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
> 
> Who will free dev on driver unload? Please make use of devm_kzalloc().

Ok. kfree is missing is disconnect().
I'll replace it by devm_kzalloc() and devm_free().

> 
> > +	if (!dev)
> > +		return -ENOMEM;
> > +
> > +	dev->udev = interface_to_usbdev(intf);
> > +
> > +	init_usb_anchor(&dev->rx_submitted);
> > +
> > +	usb_set_intfdata(intf, dev);
> > +
> > +	if (kvaser_usb_send_simple_msg(dev, CMD_RESET_CHIP, 0)) {
> > +		dev_err(&intf->dev, "Cannot reset kvaser\n");
> > +		goto error;
> > +	}
> > +
> > +	if (kvaser_usb_get_software_info(dev)) {
> > +		dev_err(&intf->dev, "Cannot get software infos\n");
> > +		goto error;
> > +	}
> > +
> > +	if (kvaser_usb_get_card_info(dev)) {
> > +		dev_err(&intf->dev, "Cannot get card infos\n");
> > +		goto error;
> > +	}
> > +
> > +	dev_dbg(&intf->dev, "Firmware version: %d.%d.%d\n",
> > +		 ((dev->fw_version >> 24) & 0xff),
> > +		 ((dev->fw_version >> 16) & 0xff),
> > +		 (dev->fw_version & 0xffff));
> > +
> > +	for (i = 0; i < dev->nchannels; i++)
> > +		kvaser_usb_init_one(intf, id, i);
> > +
> > +	return 0;
> > +
> > +error:
> > +	kfree(dev);
> > +	return err;
> > +}
> > +
> > +static void kvaser_usb_disconnect(struct usb_interface *intf)
> > +{
> > +	struct kvaser_usb *dev = usb_get_intfdata(intf);
> > +	int i;
> > +
> > +	usb_set_intfdata(intf, NULL);
> > +
> > +	if (!dev)
> > +		return;
> > +
> > +	for (i = 0; i < dev->nchannels; i++) {
> > +		if (!dev->nets[i])
> > +			continue;
> > +
> > +		unregister_netdev(dev->nets[i]->netdev);
> > +		free_candev(dev->nets[i]->netdev);
> > +	}
> > +
> > +	kvaser_usb_unlink_all_urbs(dev);
> > +}
> > +
> > +static struct usb_driver kvaser_usb_driver = {
> > +	.name = "kvaser_usb",
> > +	.probe = kvaser_usb_probe,
> > +	.disconnect = kvaser_usb_disconnect,
> > +	.id_table = kvaser_usb_table
> > +};
> > +
> > +module_usb_driver(kvaser_usb_driver);
> > +
> > +MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
> > +MODULE_DESCRIPTION("Can driver for Kvaser CAN/USB devices");
> > +MODULE_LICENSE("GPL v2");
> > diff --git a/drivers/net/can/usb/kvaser_usb.h b/drivers/net/can/usb/kvaser_usb.h
> > new file mode 100644
> > index 0000000..8e0b6ab
> > --- /dev/null
> > +++ b/drivers/net/can/usb/kvaser_usb.h
> > @@ -0,0 +1,237 @@
> > +#ifndef _KVASER_USB_H_
> > +#define _KVASER_USB_H_
> > +
> > +#define	MAX_TX_URBS			16
> Please no tab between define and macro name

Ok I didn't know it was not allowed... checkpatch didn't complain.

> > +#define	MAX_RX_URBS			4
> > +#define	START_TIMEOUT			1000
> > +#define	STOP_TIMEOUT			1000
> > +#define	USB_SEND_TIMEOUT		1000
> > +#define	USB_RECEIVE_TIMEOUT		1000
> > +#define	RX_BUFFER_SIZE			3072
> > +#define	CAN_USB_CLOCK			8000000
> > +#define	MAX_NET_DEVICES			3
> > +
> > +/* Kvaser USB devices */
> > +#define	KVASER_VENDOR_ID		0x0bfd
> > +#define	USB_LEAF_DEVEL_PRODUCT_ID	10
> > +#define	USB_LEAF_LITE_PRODUCT_ID	11
> > +#define	USB_LEAF_PRO_PRODUCT_ID		12
> > +#define	USB_LEAF_SPRO_PRODUCT_ID	14
> > +#define	USB_LEAF_PRO_LS_PRODUCT_ID	15
> > +#define	USB_LEAF_PRO_SWC_PRODUCT_ID	16
> > +#define	USB_LEAF_PRO_LIN_PRODUCT_ID	17
> > +#define	USB_LEAF_SPRO_LS_PRODUCT_ID	18
> > +#define	USB_LEAF_SPRO_SWC_PRODUCT_ID	19
> > +#define	USB_MEMO2_DEVEL_PRODUCT_ID	22
> > +#define	USB_MEMO2_HSHS_PRODUCT_ID	23
> > +#define	USB_UPRO_HSHS_PRODUCT_ID	24
> > +#define	USB_LEAF_LITE_GI_PRODUCT_ID	25
> > +#define	USB_LEAF_PRO_OBDII_PRODUCT_ID	26
> > +#define	USB_MEMO2_HSLS_PRODUCT_ID	27
> > +#define	USB_LEAF_LITE_CH_PRODUCT_ID	28
> > +#define	USB_BLACKBIRD_SPRO_PRODUCT_ID	29
> > +#define	USB_OEM_MERCURY_PRODUCT_ID	34
> > +#define	USB_OEM_LEAF_PRODUCT_ID		35
> > +#define	USB_CAN_R_PRODUCT_ID		39
> > +
> > +/* USB devices features */
> > +#define	KVASER_HAS_SILENT_MODE		(1 << 0)
> pleae use BIT(0)
> > +
> > +/* Message header size */
> > +#define	MSG_HEADER_LEN			2
> > +
> > +/* Can message flags */
> > +#define	MSG_FLAG_ERROR_FRAME		(1 << 0)
> > +#define	MSG_FLAG_OVERRUN		(1 << 1)
> > +#define	MSG_FLAG_NERR			(1 << 2)
> > +#define	MSG_FLAG_WAKEUP			(1 << 3)
> > +#define	MSG_FLAG_REMOTE_FRAME		(1 << 4)
> > +#define	MSG_FLAG_RESERVED		(1 << 5)
> > +#define	MSG_FLAG_TX_ACK			(1 << 6)
> > +#define	MSG_FLAG_TX_REQUEST		(1 << 7)
> > +
> > +/* Can states */
> > +#define	M16C_STATE_BUS_RESET		(1 << 0)
> > +#define	M16C_STATE_BUS_ERROR		(1 << 4)
> > +#define	M16C_STATE_BUS_PASSIVE		(1 << 5)
> > +#define	M16C_STATE_BUS_OFF		(1 << 6)
> > +
> > +/* Can msg ids */
> > +#define	CMD_RX_STD_MESSAGE		12
> > +#define	CMD_TX_STD_MESSAGE		13
> > +#define	CMD_RX_EXT_MESSAGE		14
> > +#define	CMD_TX_EXT_MESSAGE		15
> > +#define	CMD_SET_BUS_PARAMS		16
> > +#define	CMD_GET_BUS_PARAMS		17
> > +#define	CMD_GET_BUS_PARAMS_REPLY	18
> > +#define	CMD_GET_CHIP_STATE		19
> > +#define	CMD_CHIP_STATE_EVENT		20
> > +#define	CMD_SET_CTRL_MODE		21
> > +#define	CMD_GET_CTRL_MODE		22
> > +#define	CMD_GET_CTRL_MODE_REPLY		23
> > +#define	CMD_RESET_CHIP			24
> > +#define	CMD_RESET_CHIP_REPLY		25
> > +#define	CMD_START_CHIP			26
> > +#define	CMD_START_CHIP_REPLY		27
> > +#define	CMD_STOP_CHIP			28
> > +#define	CMD_STOP_CHIP_REPLY		29
> > +#define	CMD_GET_CARD_INFO2		32
> > +#define	CMD_GET_CARD_INFO		34
> > +#define	CMD_GET_CARD_INFO_REPLY		35
> > +#define	CMD_GET_SOFTWARE_INFO		38
> > +#define	CMD_GET_SOFTWARE_INFO_REPLY	39
> > +#define	CMD_ERROR_EVENT			45
> > +#define	CMD_FLUSH_QUEUE			48
> > +#define	CMD_TX_ACKNOWLEDGE		50
> > +#define	CMD_CAN_ERROR_EVENT		51
> > +#define	CMD_USB_THROTTLE		77
> > +
> > +/* error factors */
> > +#define	M16C_EF_ACKE			(1 << 0)
> > +#define	M16C_EF_CRCE			(1 << 1)
> > +#define	M16C_EF_FORME			(1 << 2)
> > +#define	M16C_EF_STFE			(1 << 3)
> > +#define	M16C_EF_BITE0			(1 << 4)
> > +#define	M16C_EF_BITE1			(1 << 5)
> > +#define	M16C_EF_RCVE			(1 << 6)
> > +#define	M16C_EF_TRE			(1 << 7)
> > +
> > +/* bittiming parameters */
> > +#define	KVASER_USB_TSEG1_MIN		1
> > +#define	KVASER_USB_TSEG1_MAX		16
> > +#define	KVASER_USB_TSEG2_MIN		1
> > +#define	KVASER_USB_TSEG2_MAX		8
> > +#define	KVASER_USB_SJW_MAX		4
> > +#define	KVASER_USB_BRP_MIN		1
> > +#define	KVASER_USB_BRP_MAX		64
> > +#define	KVASER_USB_BRP_INC		1
> > +
> > +/* ctrl modes */
> > +#define	KVASER_CTRL_MODE_NORMAL		1
> > +#define	KVASER_CTRL_MODE_SILENT		2
> > +#define	KVASER_CTRL_MODE_SELFRECEPTION	3
> > +#define	KVASER_CTRL_MODE_OFF		4
> > +
> > +struct kvaser_msg_simple {
> > +	u8 tid;
> > +	u8 channel;
> > +} __packed;
> > +
> > +struct kvaser_msg_cardinfo {
> > +	u8 tid;
> > +	u8 nchannels;
> > +	__le32 serial_number;
> > +	__le32 padding;
> > +	__le32 clock_resolution;
> > +	__le32 mfgdate;
> > +	u8 ean[8];
> > +	u8 hw_revision;
> > +	u8 usb_hs_mode;
> > +	__le16 padding2;
> > +} __packed;
> > +
> > +struct kvaser_msg_cardinfo2 {
> > +	u8 tid;
> > +	u8 channel;
> > +	u8 pcb_id[24];
> > +	__le32 oem_unlock_code;
> > +} __packed;
> > +
> > +struct kvaser_msg_softinfo {
> > +	u8 tid;
> > +	u8 channel;
> > +	__le32 sw_options;
> > +	__le32 fw_version;
> > +	__le16 max_outstanding_tx;
> > +	__le16 padding[9];
> > +} __packed;
> > +
> > +struct kvaser_msg_busparams {
> > +	u8 tid;
> > +	u8 channel;
> > +	__le32 bitrate;
> > +	u8 tseg1;
> > +	u8 tseg2;
> > +	u8 sjw;
> > +	u8 no_samp;
> > +} __packed;
> > +
> > +struct kvaser_msg_tx_can {
> > +	u8 channel;
> > +	u8 tid;
> > +	u8 msg[14];
> > +	u8 padding;
> > +	u8 flags;
> > +} __packed;
> > +
> > +struct kvaser_msg_rx_can {
> > +	u8 channel;
> > +	u8 flag;
> > +	__le16 time[3];
> > +	u8 msg[14];
> > +} __packed;
> > +
> > +struct kvaser_msg_chip_state_event {
> > +	u8 tid;
> > +	u8 channel;
> > +	__le16 time[3];
> > +	u8 tx_errors_count;
> > +	u8 rx_errors_count;
> > +	u8 status;
> > +	u8 padding[3];
> > +} __packed;
> > +
> > +struct kvaser_msg_tx_acknowledge {
> > +	u8 channel;
> > +	u8 tid;
> > +	__le16 time[3];
> > +	u8 flags;
> > +	u8 time_offset;
> > +} __packed;
> > +
> > +struct kvaser_msg_error_event {
> > +	u8 tid;
> > +	u8 flags;
> > +	__le16 time[3];
> > +	u8 channel;
> > +	u8 padding;
> > +	u8 tx_errors_count;
> > +	u8 rx_errors_count;
> > +	u8 status;
> > +	u8 error_factor;
> > +} __packed;
> > +
> > +struct kvaser_msg_ctrl_mode {
> > +	u8 tid;
> > +	u8 channel;
> > +	u8 ctrl_mode;
> > +	u8 padding[3];
> > +} __packed;
> > +
> > +struct kvaser_msg_flush_queue {
> > +	u8 tid;
> > +	u8 channel;
> > +	u8 flags;
> > +	u8 padding[3];
> > +} __packed;
> > +
> > +struct kvaser_msg {
> > +	u8 len;
> > +	u8 id;
> > +	union	{
> > +		struct kvaser_msg_simple simple;
> > +		struct kvaser_msg_cardinfo cardinfo;
> > +		struct kvaser_msg_cardinfo2 cardinfo2;
> > +		struct kvaser_msg_softinfo softinfo;
> > +		struct kvaser_msg_busparams busparams;
> > +		struct kvaser_msg_tx_can tx_can;
> > +		struct kvaser_msg_rx_can rx_can;
> > +		struct kvaser_msg_chip_state_event chip_state_event;
> > +		struct kvaser_msg_tx_acknowledge tx_acknowledge;
> > +		struct kvaser_msg_error_event error_event;
> > +		struct kvaser_msg_ctrl_mode ctrl_mode;
> > +		struct kvaser_msg_ctrl_mode flush_queue;
> > +	} u;
> > +} __packed;
> > +
> > +#endif
> > 
> 
> 
> -- 
> Pengutronix e.K.                  | Marc Kleine-Budde           |
> Industrial Linux Solutions        | Phone: +49-231-2826-924     |
> Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
> Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |
> 

Thanks for the review.
Regards,

On 07/30/2012 03:33 PM, Olivier Sobrie wrote:
> Hi Marc,
> 
> On Mon, Jul 30, 2012 at 01:11:46PM +0200, Marc Kleine-Budde wrote:
>> On 07/30/2012 07:32 AM, Olivier Sobrie wrote:
>>> This driver provides support for several Kvaser CAN/USB devices.
>>> Such kind of devices supports up to three can network interfaces.
>>>
>>> It has been tested with a Kvaser USB Leaf Light (one network interface)
>>> connected to a pch_can interface.
>>> The firmware version of the Kvaser device was 2.5.205.
>>
>> Please add linux-usb@vger.kernel.org to Cc for review of the USB part.
> 
> Ok I'll do it when I send the new version of the patch.
> But it might be a good idea to add an entry in the MAINTAINERS file so
> that when someone sends a patch they are aware of this when the
> get_maintainer script is invoked.

Interesting Idea. We should discuss this here, however we should not
bother the USB List when sending USB unrelated patches.

>> Please combine .h and .c file. Please make use of netdev_LEVEL() for
>> error printing, not dev_LEVEL().
> 
> I'll combine the .c and .h.
> I used the netdev_LEVEL() everywhere it was possible. It requires to
> have access to a pointer to netdev which is not always possible;
> that's the reason why I used dev_LEVEL().

I see, you used it when channel is invalid. So you have obviously no netdev.

>> Please review if all members of the struct kvaser_msg are properly
>> aligned. You never access the struct kvaser_msg_* members directly, as
>> they are unaligned. Please check for le16 and le32 access. You missed to
>> convert the bitrate.
> 
> Indeed. Thanks. I'll check if I didn't missed another one.

Tnx

>> Please check if your driver survives hot-unplugging while sending and
>> receiving CAN frames at maximum laod.
> 
> I tested this with two Kvaser sending frames with "cangen can0 -g 0 -i"
> never saw a crash.

Please test send sending and receiving at the same time.

>> More comments inline,
>> regards, Marc
>>
>>> List of Kvaser devices supported by the driver:
>>>   - Kvaser Leaf prototype (P010v2 and v3)
>>>   - Kvaser Leaf Light (P010v3)
>>>   - Kvaser Leaf Professional HS
>>>   - Kvaser Leaf SemiPro HS
>>>   - Kvaser Leaf Professional LS
>>>   - Kvaser Leaf Professional SWC
>>>   - Kvaser Leaf Professional LIN
>>>   - Kvaser Leaf SemiPro LS
>>>   - Kvaser Leaf SemiPro SWC
>>>   - Kvaser Memorator II, Prototype
>>>   - Kvaser Memorator II HS/HS
>>>   - Kvaser USBcan Professional HS/HS
>>>   - Kvaser Leaf Light GI
>>>   - Kvaser Leaf Professional HS (OBD-II connector)
>>>   - Kvaser Memorator Professional HS/LS
>>>   - Kvaser Leaf Light "China"
>>>   - Kvaser BlackBird SemiPro
>>>   - Kvaser OEM Mercury
>>>   - Kvaser OEM Leaf
>>>   - Kvaser USBcan R
>>>
>>> Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
>>> ---
>>>  drivers/net/can/usb/Kconfig      |   33 ++
>>>  drivers/net/can/usb/Makefile     |    1 +
>>>  drivers/net/can/usb/kvaser_usb.c | 1062 ++++++++++++++++++++++++++++++++++++++
>>>  drivers/net/can/usb/kvaser_usb.h |  237 +++++++++
>>>  4 files changed, 1333 insertions(+)
>>>  create mode 100644 drivers/net/can/usb/kvaser_usb.c
>>>  create mode 100644 drivers/net/can/usb/kvaser_usb.h
>>>
>>> diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
>>> index 0a68768..578955f 100644
>>> --- a/drivers/net/can/usb/Kconfig
>>> +++ b/drivers/net/can/usb/Kconfig
>>> @@ -13,6 +13,39 @@ config CAN_ESD_USB2
>>>            This driver supports the CAN-USB/2 interface
>>>            from esd electronic system design gmbh (http://www.esd.eu).
>>>  
>>> +config CAN_KVASER_USB
>>> +	tristate "Kvaser CAN/USB interface"
>>> +	---help---
>>> +	  This driver adds support for Kvaser CAN/USB devices like Kvaser
>>> +	  Leaf Light.
>>> +
>>> +	  The driver gives support for the following devices:
>>> +	    - Kvaser Leaf prototype (P010v2 and v3)
>>> +	    - Kvaser Leaf Light (P010v3)
>>> +	    - Kvaser Leaf Professional HS
>>> +	    - Kvaser Leaf SemiPro HS
>>> +	    - Kvaser Leaf Professional LS
>>> +	    - Kvaser Leaf Professional SWC
>>> +	    - Kvaser Leaf Professional LIN
>>> +	    - Kvaser Leaf SemiPro LS
>>> +	    - Kvaser Leaf SemiPro SWC
>>> +	    - Kvaser Memorator II, Prototype
>>> +	    - Kvaser Memorator II HS/HS
>>> +	    - Kvaser USBcan Professional HS/HS
>>> +	    - Kvaser Leaf Light GI
>>> +	    - Kvaser Leaf Professional HS (OBD-II connector)
>>> +	    - Kvaser Memorator Professional HS/LS
>>> +	    - Kvaser Leaf Light "China"
>>> +	    - Kvaser BlackBird SemiPro
>>> +	    - Kvaser OEM Mercury
>>> +	    - Kvaser OEM Leaf
>>> +	    - Kvaser USBcan R
>>> +
>>> +	  If unsure, say N.
>>> +
>>> +	  To compile this driver as a module, choose M here: the
>>> +	  module will be called kvaser_usb.
>>> +
>>>  config CAN_PEAK_USB
>>>  	tristate "PEAK PCAN-USB/USB Pro interfaces"
>>>  	---help---
>>> diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
>>> index da6d1d3..80a2ee4 100644
>>> --- a/drivers/net/can/usb/Makefile
>>> +++ b/drivers/net/can/usb/Makefile
>>> @@ -4,6 +4,7 @@
>>>  
>>>  obj-$(CONFIG_CAN_EMS_USB) += ems_usb.o
>>>  obj-$(CONFIG_CAN_ESD_USB2) += esd_usb2.o
>>> +obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o
>>>  obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
>>>  
>>>  ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
>>> diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
>>> new file mode 100644
>>> index 0000000..4965480
>>> --- /dev/null
>>> +++ b/drivers/net/can/usb/kvaser_usb.c
>>> @@ -0,0 +1,1062 @@
>>> +/*
>>
>> Please add a license statement and probably your copyright:
>>
>>  * This program is free software; you can redistribute it and/or
>>  * modify it under the terms of the GNU General Public License as
>>  * published by the Free Software Foundation version 2.
>>
>> You also should copy the copyright from the drivers you used:
>>
>>> + * Parts of this driver are based on the following:
>>> + *  - Kvaser linux leaf driver (version 4.78)
>>
>> I just downloaded their driver and noticed that it's quite sparse on
>> stating the license the code is released under.
>> "doc/HTMLhelp/copyright.htx" is quite restrictive, the word GPL occurs 3
>> times, all in MODULE_LICENSE("GPL"). Running modinfo on the usbcan.ko
>> shows "license: GPL"
> 
> I'll add the license statement.
> In fact it's the leaf.ko which is used for this device and it is under
> GPL as modinfo said.

I just talked to my boss and we're the same opinion, that
MODULE_LICENSE("GPL") is a technical term and not relevant if the
included license doesn't say a word about GPL. If the kvaser tarball
violates the GPL, however is written on different sheet of paper (as we
say in Germany).

So I cannot put my S-o-b under this driver as long as we haven't talked
to kvaser.

>>> + *  - CAN driver for esd CAN-USB/2
>>> + */
>>> +
>>> +#include <linux/init.h>
>>> +#include <linux/completion.h>
>>> +#include <linux/module.h>
>>> +#include <linux/netdevice.h>
>>> +#include <linux/usb.h>
>>> +
>>> +#include <linux/can.h>
>>> +#include <linux/can/dev.h>
>>> +#include <linux/can/error.h>
>>> +
>>> +#include "kvaser_usb.h"
>>> +
>>> +struct kvaser_usb_tx_urb_context {
>>> +	struct kvaser_usb_net_priv *priv;
>>
>> Huh - how does this work without forward declaration?
> 
> It works.

Yes, obviously :)

> "In C and C++ it is possible to declare pointers to structs before
> declaring their struct layout, provided the pointers are not
> dereferenced--this is known as forward declaration."
> 
> See http://www.linuxtopia.org/online_books/an_introduction_to_gcc/gccintro_94.html

Thanks for the link.
>>
>>> +	u32 echo_index;
>>> +	int dlc;
>>> +};
>>> +
>>> +struct kvaser_usb {
>>> +	struct usb_device *udev;
>>> +	struct kvaser_usb_net_priv *nets[MAX_NET_DEVICES];
>>> +
>>> +	struct usb_anchor rx_submitted;
>>> +
>>> +	u32 fw_version;
>>> +	unsigned int nchannels;
>>> +
>>> +	bool rxinitdone;
>>> +};
>>> +
>>> +struct kvaser_usb_net_priv {
>>> +	struct can_priv can;
>>> +
>>> +	atomic_t active_tx_urbs;
>>> +	struct usb_anchor tx_submitted;
>>> +	struct kvaser_usb_tx_urb_context tx_contexts[MAX_TX_URBS];
>>> +
>>> +	int open_time;
>>
>> please remove open_time
> 
> Ok.
> 
>>
>>> +	struct completion start_stop_comp;
>>> +
>>> +	struct kvaser_usb *dev;
>>> +	struct net_device *netdev;
>>> +	int channel;
>>> +	struct can_berr_counter bec;
>>> +};
>>> +
>>> +static struct usb_device_id kvaser_usb_table[] = {
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_DEVEL_PRODUCT_ID) },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_PRODUCT_ID) },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_PRODUCT_ID),
>>> +		.driver_info = KVASER_HAS_SILENT_MODE },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_PRODUCT_ID),
>>> +		.driver_info = KVASER_HAS_SILENT_MODE },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_LS_PRODUCT_ID),
>>> +		.driver_info = KVASER_HAS_SILENT_MODE },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_SWC_PRODUCT_ID),
>>> +		.driver_info = KVASER_HAS_SILENT_MODE },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_LIN_PRODUCT_ID),
>>> +		.driver_info = KVASER_HAS_SILENT_MODE },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_LS_PRODUCT_ID),
>>> +		.driver_info = KVASER_HAS_SILENT_MODE },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_SWC_PRODUCT_ID),
>>> +		.driver_info = KVASER_HAS_SILENT_MODE },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_DEVEL_PRODUCT_ID),
>>> +		.driver_info = KVASER_HAS_SILENT_MODE },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_HSHS_PRODUCT_ID),
>>> +		.driver_info = KVASER_HAS_SILENT_MODE },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_UPRO_HSHS_PRODUCT_ID) },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_GI_PRODUCT_ID) },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_OBDII_PRODUCT_ID),
>>> +		.driver_info = KVASER_HAS_SILENT_MODE },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_HSLS_PRODUCT_ID) },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_CH_PRODUCT_ID) },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_BLACKBIRD_SPRO_PRODUCT_ID) },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_OEM_MERCURY_PRODUCT_ID) },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_OEM_LEAF_PRODUCT_ID) },
>>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_CAN_R_PRODUCT_ID) },
>>> +	{ }
>>> +};
>>> +MODULE_DEVICE_TABLE(usb, kvaser_usb_table);
>>> +
>>> +static int kvaser_usb_send_msg(const struct kvaser_usb *dev,
>>> +			       struct kvaser_msg *msg)
>> inline?
> 
> Ok.
> 
>>> +{
>>> +	int actual_len;
>>> +
>>> +	return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 1),
>>                                                                   ^
>> Can you please introduce a #define for this.
> 
> Ok. No problem.
> 
>>
>>> +			    msg, msg->len, &actual_len, USB_SEND_TIMEOUT);
>>> +}
>>> +
>>> +static int kvaser_usb_wait_msg(const struct kvaser_usb *dev, u8 id,
>>> +			       struct kvaser_msg *msg)
>>> +{
>>> +	struct kvaser_msg *tmp;
>>> +	void *buf;
>>> +	int actual_len;
>>> +	int err;
>>> +	int pos = 0;
>>> +
>>> +	buf = kzalloc(RX_BUFFER_SIZE, GFP_KERNEL);
>>> +	if (!buf)
>>> +		return -ENOMEM;
>>> +
>>> +	err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, 129),
>>                                                                  ^^^
>> dito
> 
> Ok too.
> 
>>
>>> +			   buf, RX_BUFFER_SIZE, &actual_len,
>>> +			   USB_RECEIVE_TIMEOUT);
>>> +	if (err < 0) {
>>> +		kfree(buf);
>>> +		return err;
>>> +	}
>>> +
>>> +	while (pos < actual_len) {
>>
>> Please check that pos + sizeof(*msg) is < actual_len, as you fill access
>> it later.
> 
> I'll instead perform a check on 'pos + tmp->len < actual_len' and copy
> only tmp->len instead of sizeof(*msg).
> Thanks.

Even better, saves some bytes to be copied. Take care not to deref tmp,
unless you checked that tmp is in valid memory.

>>
>>> +		tmp = buf + pos;
>>> +
>>> +		if (!tmp->len)
>>> +			break;
>>> +
>>> +		if (tmp->id == id) {
>>> +			memcpy(msg, tmp, sizeof(*msg));
>>> +			kfree(buf);
>>> +			return 0;
>>> +		}
>>> +
>>> +		pos += tmp->len;
>>> +	}
>>> +
>>> +	kfree(buf);
>>> +
>>> +	return -EINVAL;
>>> +}
>>> +
>>> +static int kvaser_usb_send_simple_msg(const struct kvaser_usb *dev,
>>> +				      u8 msg_id, int channel)
>>> +{
>>> +	struct kvaser_msg msg;
>>> +	int err;
>>> +
>>> +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_simple);
>>> +	msg.id = msg_id;
>>> +	msg.u.simple.channel = channel;
>>> +	msg.u.simple.tid = 0xff;
>>
>> Please use C99 struct initializer.
>>
>> struct kvaser_msg msg = {
>> 	.len = ,
>> 	.id =,
>> };
> 
> Ok.
> 
>>
>>
>>> +
>>> +	err = kvaser_usb_send_msg(dev, &msg);
>>
>> 	just:
>> 	return err;
> 
> Ok.
> 
>>
>>> +	if (err)
>>> +		return err;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int kvaser_usb_get_software_info(struct kvaser_usb *dev)
>>> +{
>>> +	struct kvaser_msg msg;
>>> +	int err;
>>> +
>>> +	err = kvaser_usb_send_simple_msg(dev, CMD_GET_SOFTWARE_INFO, 0);
>>> +	if (err)
>>> +		return err;
>>> +
>>> +	err = kvaser_usb_wait_msg(dev, CMD_GET_SOFTWARE_INFO_REPLY, &msg);
>>> +	if (err)
>>> +		return err;
>>> +
>>> +	dev->fw_version = le32_to_cpu(msg.u.softinfo.fw_version);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int kvaser_usb_get_card_info(struct kvaser_usb *dev)
>>> +{
>>> +	struct kvaser_msg msg;
>>> +	int err;
>>> +
>>> +	err = kvaser_usb_send_simple_msg(dev, CMD_GET_CARD_INFO, 0);
>>> +	if (err)
>>> +		return err;
>>> +
>>> +	err = kvaser_usb_wait_msg(dev, CMD_GET_CARD_INFO_REPLY, &msg);
>>> +	if (err)
>>> +		return err;
>>> +
>>> +	dev->nchannels = msg.u.cardinfo.nchannels;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static void kvaser_usb_tx_acknowledge(const struct kvaser_usb *dev,
>>> +				      const struct kvaser_msg *msg)
>>> +{
>>> +	struct net_device_stats *stats;
>>> +	struct kvaser_usb_tx_urb_context *context;
>>> +	struct kvaser_usb_net_priv *priv;
>>> +	u8 channel = msg->u.tx_acknowledge.channel;
>>> +	u8 tid = msg->u.tx_acknowledge.tid;
>>> +
>>> +	if (channel >= dev->nchannels) {
>>> +		dev_err(dev->udev->dev.parent,
>>> +			"Invalid channel number (%d)\n", channel);
>>> +		return;
>>> +	}
>>
>> can you do a check for (channel >= dev->nchannels), in a central place?
>> e.g. kvaser_usb_handle_message()?
> 
> The problem is that channel is not always at the same place in the
> messages I get from the hardware. 'tid' and 'channel' are inverted for
> tx and rx frames.
> e.g.

Grr...who's written that firmware :D

> 
> struct kvaser_msg_tx_can {
>         u8 channel;
>         u8 tid;
>         u8 msg[14];
>         u8 padding;
>         u8 flags;
> } __packed;
> 
> struct kvaser_msg_busparams {
>         u8 tid;
>         u8 channel;
>         __le32 bitrate;
>         u8 tseg1;
>         u8 tseg2;
>         u8 sjw;
>         u8 no_samp;
> } __packed;
> 
>>
>>> +
>>> +	priv = dev->nets[channel];
>>> +
>>> +	if (!netif_device_present(priv->netdev))
>>> +		return;
>>> +
>>> +	stats = &priv->netdev->stats;
>>> +
>>> +	context = &priv->tx_contexts[tid % MAX_TX_URBS];
>>> +
>>> +	/*
>>> +	 * It looks like the firmware never sets the flags field of the
>>> +	 * tx_acknowledge frame and never reports a transmit failure.
>>> +	 * If the can message can't be transmited (e.g. incompatible
>>> +	 * bitrates), a frame CMD_CAN_ERROR_EVENT is sent (with a null
>>> +	 * tid) and the firmware tries to transmit again the packet until
>>> +	 * it succeeds. Once the packet is successfully transmitted, then
>>> +	 * the tx_acknowledge frame is sent.
>>> +	 */
>>> +
>>> +	stats->tx_packets++;
>>> +	stats->tx_bytes += context->dlc;
>>> +	can_get_echo_skb(priv->netdev, context->echo_index);
>>> +
>>> +	context->echo_index = MAX_TX_URBS;
>>> +	atomic_dec(&priv->active_tx_urbs);
>>> +
>>> +	netif_wake_queue(priv->netdev);
>>> +}
>>> +
>>> +static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
>>> +				const struct kvaser_msg *msg)
>>> +{
>>> +	struct can_frame *cf;
>>> +	struct sk_buff *skb;
>>> +	struct net_device_stats *stats;
>>> +	struct kvaser_usb_net_priv *priv;
>>> +	u8 channel, status, txerr, rxerr;
>>> +
>>> +	if (msg->id == CMD_CAN_ERROR_EVENT) {
>>> +		channel = msg->u.error_event.channel;
>>> +		status =  msg->u.error_event.status;
>>> +		txerr = msg->u.error_event.tx_errors_count;
>>> +		rxerr = msg->u.error_event.rx_errors_count;
>>> +	} else {
>>> +		channel = msg->u.chip_state_event.channel;
>>> +		status =  msg->u.chip_state_event.status;
>>> +		txerr = msg->u.chip_state_event.tx_errors_count;
>>> +		rxerr = msg->u.chip_state_event.rx_errors_count;
>>> +	}
>>> +
>>> +	if (channel >= dev->nchannels) {
>>> +		dev_err(dev->udev->dev.parent,
>>> +			"Invalid channel number (%d)\n", channel);
>>> +		return;
>>> +	}
>>> +
>>> +	priv = dev->nets[channel];
>>> +	stats = &priv->netdev->stats;
>>> +
>>> +	skb = alloc_can_err_skb(priv->netdev, &cf);
>>> +	if (!skb) {
>>> +		stats->rx_dropped++;
>>> +		return;
>>> +	}
>>> +
>>> +	if ((status & M16C_STATE_BUS_OFF) ||
>>> +	    (status & M16C_STATE_BUS_RESET)) {
>>> +		priv->can.state = CAN_STATE_BUS_OFF;
>>> +		cf->can_id |= CAN_ERR_BUSOFF;
>>> +		can_bus_off(priv->netdev);

you should increment priv->can.can_stats.bus_off
What does the firmware do in this state? Does it automatically try to
recover and try to send the outstanding frames?

If so, you should turn of the CAN interface, it possible. See:
http://lxr.free-electrons.com/source/drivers/net/can/at91_can.c#L986

Please test Bus-Off behaviour:
- setup working CAN network
- short circuit CAN-H and CAN-L wires
- start "candump any,0:0,#FFFFFFFF" on one shell
- send one can frame on the other

then

- remove the short circuit
- see if the can frame is transmitted to the other side
- it should show up as an echo'ed CAN frame on the sender side

Repeat the same test with disconnecting CAN-H and CAN-L from the other
CAN station instead of short circuit.

Please send the output from candump.

>>> +	} else if (status & M16C_STATE_BUS_ERROR) {
>>> +		priv->can.state = CAN_STATE_ERROR_WARNING;
>>> +		priv->can.can_stats.error_warning++;
>>> +	} else if (status & M16C_STATE_BUS_PASSIVE) {
>>> +		priv->can.state = CAN_STATE_ERROR_PASSIVE;
>>> +		priv->can.can_stats.error_passive++;
>>> +	} else {
>>> +		priv->can.state = CAN_STATE_ERROR_ACTIVE;
>>> +		cf->can_id |= CAN_ERR_PROT;
>>> +		cf->data[2] = CAN_ERR_PROT_ACTIVE;
>>> +	}
>>> +
>>> +	if (msg->id == CMD_CAN_ERROR_EVENT) {
>>> +		u8 error_factor = msg->u.error_event.error_factor;
>>> +
>>> +		priv->can.can_stats.bus_error++;
>>> +		stats->rx_errors++;
>>> +
>>> +		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
>>> +
>>> +		if ((priv->can.state == CAN_STATE_ERROR_WARNING) ||
>>> +		    (priv->can.state == CAN_STATE_ERROR_PASSIVE)) {
>>> +			cf->data[1] = (txerr > rxerr) ?
>>> +				CAN_ERR_CRTL_TX_PASSIVE
>>> +				: CAN_ERR_CRTL_RX_PASSIVE;
>>> +		}
>>> +
>>> +		if (error_factor & M16C_EF_ACKE)
>>> +			cf->data[3] |= (CAN_ERR_PROT_LOC_ACK |
>>> +					CAN_ERR_PROT_LOC_ACK_DEL);
>>> +		if (error_factor & M16C_EF_CRCE)
>>> +			cf->data[3] |= (CAN_ERR_PROT_LOC_CRC_SEQ |
>>> +					CAN_ERR_PROT_LOC_CRC_DEL);
>>> +		if (error_factor & M16C_EF_FORME)
>>> +			cf->data[2] |= CAN_ERR_PROT_FORM;
>>> +		if (error_factor & M16C_EF_STFE)
>>> +			cf->data[2] |= CAN_ERR_PROT_STUFF;
>>> +		if (error_factor & M16C_EF_BITE0)
>>> +			cf->data[2] |= CAN_ERR_PROT_BIT0;
>>> +		if (error_factor & M16C_EF_BITE1)
>>> +			cf->data[2] |= CAN_ERR_PROT_BIT1;
>>> +		if (error_factor & M16C_EF_TRE)
>>> +			cf->data[2] |= CAN_ERR_PROT_TX;
>>> +	}
>>> +
>>> +	cf->data[6] = txerr;
>>> +	cf->data[7] = rxerr;
>>> +
>>> +	netif_rx(skb);
>>> +
>>> +	priv->bec.txerr = txerr;
>>> +	priv->bec.rxerr = rxerr;
>>> +
>>> +	stats->rx_packets++;
>>> +	stats->rx_bytes += cf->can_dlc;
>>> +}
>>> +
>>> +static void kvaser_usb_rx_can_msg(const struct kvaser_usb *dev,
>>> +				  const struct kvaser_msg *msg)
>>> +{
>>> +	struct kvaser_usb_net_priv *priv;
>>> +	struct can_frame *cf;
>>> +	struct sk_buff *skb;
>>> +	struct net_device_stats *stats;
>>> +	u8 channel = msg->u.rx_can.channel;
>>> +
>>> +	if (channel >= dev->nchannels) {
>>> +		dev_err(dev->udev->dev.parent,
>>> +			"Invalid channel number (%d)\n", channel);
>>> +		return;
>>> +	}
>>> +
>>> +	priv = dev->nets[channel];
>>> +	stats = &priv->netdev->stats;
>>> +
>>> +	skb = alloc_can_skb(priv->netdev, &cf);
>>> +	if (skb == NULL) {
>>> +		stats->tx_dropped++;
>>> +		return;
>>> +	}
>>> +
>>> +	cf->can_id = ((msg->u.rx_can.msg[0] & 0x1f) << 6) |
>>> +		     (msg->u.rx_can.msg[1] & 0x3f);
>>> +	cf->can_dlc = get_can_dlc(msg->u.rx_can.msg[5]);
>>> +
>>> +	if (msg->id == CMD_RX_EXT_MESSAGE) {
>>> +		cf->can_id <<= 18;
>>> +		cf->can_id += ((msg->u.rx_can.msg[2] & 0x0f) << 14) |
>>                            |=
>>
>> is more appropriate here
> 
> Ok.
> 
>>
>>> +			      ((msg->u.rx_can.msg[3] & 0xff) << 6) |
>>> +			      (msg->u.rx_can.msg[4] & 0x3f);
>>> +		cf->can_id |= CAN_EFF_FLAG;
>>> +	}
>>> +
>>> +	if (msg->u.rx_can.flag & MSG_FLAG_REMOTE_FRAME) {
>>> +		cf->can_id |= CAN_RTR_FLAG;
>>> +	} else if (msg->u.rx_can.flag & (MSG_FLAG_ERROR_FRAME |
>>> +						MSG_FLAG_NERR)) {
>>> +		cf->can_id |= CAN_ERR_FLAG;
>>> +		cf->can_dlc = CAN_ERR_DLC;
>>
>> What kind of error is this? Can you set cf->data? What about the
>> original cd->can_id? What about the stats->rx_*error* stats?
> 
> Good question I've to take a look to this.
> 
>>
>>> +	} else if (msg->u.rx_can.flag & MSG_FLAG_OVERRUN) {
>>> +		cf->can_id = CAN_ERR_FLAG | CAN_ERR_CRTL;
>>> +		cf->can_dlc = CAN_ERR_DLC;
>>> +		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
>>> +
>>> +		stats->rx_over_errors++;
>>> +		stats->rx_errors++;
>>> +	} else if (!msg->u.rx_can.flag) {
>>> +		memcpy(cf->data, &msg->u.rx_can.msg[6], cf->can_dlc);
>>> +	} else {
>>> +		kfree_skb(skb);
>>> +		return;
>>> +	}
>>> +
>>> +	netif_rx(skb);
>>> +
>>> +	stats->rx_packets++;
>>> +	stats->rx_bytes += cf->can_dlc;
>>> +}
>>> +
>>> +static void kvaser_usb_start_stop_chip_reply(const struct kvaser_usb *dev,
>>> +					     const struct kvaser_msg *msg)
>>> +{
>>> +	struct kvaser_usb_net_priv *priv;
>>> +	u8 channel = msg->u.simple.channel;
>>> +
>>> +	if (channel >= dev->nchannels) {
>>> +		dev_err(dev->udev->dev.parent,
>>> +			"Invalid channel number (%d)\n", channel);
>>> +		return;
>>> +	}
>>> +
>>> +	priv = dev->nets[channel];
>>> +
>>> +	complete(&priv->start_stop_comp);
>>> +}
>>> +
>>> +static void kvaser_usb_handle_message(const struct kvaser_usb *dev,
>>> +				      const struct kvaser_msg *msg)
>>> +{
>>> +	switch (msg->id) {
>>> +	case CMD_START_CHIP_REPLY:
>>> +	case CMD_STOP_CHIP_REPLY:
>>> +		kvaser_usb_start_stop_chip_reply(dev, msg);
>>> +		break;
>>> +
>>> +	case CMD_RX_STD_MESSAGE:
>>> +	case CMD_RX_EXT_MESSAGE:
>>> +		kvaser_usb_rx_can_msg(dev, msg);
>>> +		break;
>>> +
>>> +	case CMD_CHIP_STATE_EVENT:
>>> +	case CMD_CAN_ERROR_EVENT:
>>> +		kvaser_usb_rx_error(dev, msg);
>>> +		break;
>>> +
>>> +	case CMD_TX_ACKNOWLEDGE:
>>> +		kvaser_usb_tx_acknowledge(dev, msg);
>>> +		break;
>>> +
>>> +	default:
>>> +		dev_warn(dev->udev->dev.parent,
>>> +			 "Unhandled message (%d)\n", msg->id);
>>> +		break;
>>> +	}
>>> +}
>>> +
>>> +static void kvaser_usb_read_bulk_callback(struct urb *urb)
>>> +{
>>> +	struct kvaser_usb *dev = urb->context;
>>> +	struct kvaser_msg *msg;
>>> +	int pos = 0;
>>> +	int err, i;
>>> +
>>> +	switch (urb->status) {
>>> +	case 0:
>>> +		break;
>>> +	case -ENOENT:
>>> +	case -ESHUTDOWN:
>>> +		return;
>>> +	default:
>>> +		dev_info(dev->udev->dev.parent, "Rx URB aborted (%d)\n",
>>> +			 urb->status);
>>> +		goto resubmit_urb;
>>> +	}
>>> +
>>> +	while (pos < urb->actual_length) {
>>
>> please check here for pos + sizeof(*msg), too
> 
> Same as above.
> 
>>
>>> +		msg = urb->transfer_buffer + pos;
>>> +
>>> +		if (!msg->len)
>>> +			break;
>>> +
>>> +		kvaser_usb_handle_message(dev, msg);
>>> +
>>> +		if (pos > urb->actual_length) {
>>> +			dev_err(dev->udev->dev.parent, "Format error\n");
>>> +			break;
>>> +		}
>>> +
>>> +		pos += msg->len;
>>> +	}
>>> +
>>> +resubmit_urb:
>>> +	usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 129),
>>                                                                      ^^^
>>
>> use #define
> 
> Ok.
> 
>>
>>> +			  urb->transfer_buffer, RX_BUFFER_SIZE,
>>> +			  kvaser_usb_read_bulk_callback, dev);
>>> +
>>> +	err = usb_submit_urb(urb, GFP_ATOMIC);
>>> +	if (err == -ENODEV) {
>>> +		for (i = 0; i < dev->nchannels; i++) {
>>> +			if (!dev->nets[i])
>>> +				continue;
>>> +
>>> +			netif_device_detach(dev->nets[i]->netdev);
>>> +		}
>>> +	} else if (err) {
>>> +		dev_err(dev->udev->dev.parent,
>>> +			"Failed resubmitting read bulk urb: %d\n", err);
>>> +	}
>>> +
>>> +	return;
>>> +}
>>> +
>>> +static int kvaser_usb_setup_rx_urbs(struct kvaser_usb *dev)
>>> +{
>>> +	int i, err = 0;
>>> +
>>> +	if (dev->rxinitdone)
>>> +		return 0;
>>> +
>>> +	for (i = 0; i < MAX_RX_URBS; i++) {
>>> +		struct urb *urb = NULL;
>>> +		u8 *buf = NULL;
>>> +
>>> +		urb = usb_alloc_urb(0, GFP_KERNEL);
>>> +		if (!urb) {
>>> +			dev_warn(dev->udev->dev.parent,
>>> +				 "No memory left for URBs\n");
>>> +			err = -ENOMEM;
>>> +			break;
>>> +		}
>>> +
>>> +		buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE,
>>> +					 GFP_KERNEL, &urb->transfer_dma);
>>> +		if (!buf) {
>>> +			dev_warn(dev->udev->dev.parent,
>>> +				 "No memory left for USB buffer\n");
>>> +			usb_free_urb(urb);
>>> +			err = -ENOMEM;
>>> +			break;
>>> +		}
>>> +
>>> +		usb_fill_bulk_urb(urb, dev->udev,
>>> +				  usb_rcvbulkpipe(dev->udev, 129),
>>
>> use #define
> 
> Ok.
> 
>>
>>> +				  buf, RX_BUFFER_SIZE,
>>> +				  kvaser_usb_read_bulk_callback, dev);
>>> +		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
>>> +		usb_anchor_urb(urb, &dev->rx_submitted);
>>> +
>>> +		err = usb_submit_urb(urb, GFP_KERNEL);
>>> +		if (err) {
>>> +			usb_unanchor_urb(urb);
>>> +			usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
>>> +					  urb->transfer_dma);
>>> +			break;
>>> +		}
>>> +
>>> +		usb_free_urb(urb);
>>> +	}
>>> +
>>> +	if (i == 0) {
>>> +		dev_warn(dev->udev->dev.parent,
>>> +			 "Cannot setup read URBs, error %d\n", err);
>>> +		return err;
>>> +	} else if (i < MAX_RX_URBS) {
>>> +		dev_warn(dev->udev->dev.parent,
>>> +			 "RX performances may be slow\n");
>>> +	}
>>> +
>>> +	dev->rxinitdone = true;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int kvaser_usb_set_opt_mode(const struct kvaser_usb_net_priv *priv)
>>> +{
>>> +	struct kvaser_msg msg;
>>> +
>>> +	memset(&msg, 0x00, sizeof(msg));
>>> +	msg.id = CMD_SET_CTRL_MODE;
>>> +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_ctrl_mode);
>>> +	msg.u.ctrl_mode.tid = 0xff;
>>> +	msg.u.ctrl_mode.channel = priv->channel;
>>
>> please use C99 struct initializers
> 
> Ok.
> 
>>
>>> +
>>> +	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
>>> +		msg.u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_SILENT;
>>> +	else
>>> +		msg.u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_NORMAL;
>>> +
>>> +	return kvaser_usb_send_msg(priv->dev, &msg);
>>> +}
>>> +
>>> +static int kvaser_usb_start_chip(struct kvaser_usb_net_priv *priv)
>>> +{
>>> +	int err;
>>> +
>>> +	init_completion(&priv->start_stop_comp);
>>> +
>>> +	err = kvaser_usb_send_simple_msg(priv->dev, CMD_START_CHIP,
>>> +					 priv->channel);
>>> +	if (err)
>>> +		return err;
>>> +
>>> +	if (!wait_for_completion_timeout(&priv->start_stop_comp,
>>> +					 msecs_to_jiffies(START_TIMEOUT)))
>>> +		return -ETIMEDOUT;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int kvaser_usb_open(struct net_device *netdev)
>>> +{
>>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
>>> +	struct kvaser_usb *dev = priv->dev;
>>> +	int err;
>>> +
>>> +	err = open_candev(netdev);
>>> +	if (err)
>>> +		return err;
>>> +
>>> +	err = kvaser_usb_setup_rx_urbs(dev);
>>> +	if (err)
>>> +		return err;
>>> +
>>> +	err = kvaser_usb_set_opt_mode(priv);
>>> +	if (err)
>>> +		return err;
>>> +
>>> +	err = kvaser_usb_start_chip(priv);
>>> +	if (err) {
>>> +		netdev_warn(netdev, "Cannot start device, error %d\n", err);
>>> +		close_candev(netdev);
>>> +		return err;
>>> +	}
>>> +
>>> +	priv->can.state = CAN_STATE_ERROR_ACTIVE;
>>> +	priv->open_time = jiffies;
>>> +	netif_start_queue(netdev);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static void kvaser_usb_unlink_tx_urbs(struct kvaser_usb_net_priv *priv)
>>> +{
>>> +	int i;
>>> +
>>> +	usb_kill_anchored_urbs(&priv->tx_submitted);
>>> +	atomic_set(&priv->active_tx_urbs, 0);
>>> +
>>> +	for (i = 0; i < MAX_TX_URBS; i++)
>> ARRAY_SIZE(priv->tx_contexts) instead of MAX_TX_URBS
> 
> Ok.
> 
>>> +		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
>>> +}
>>> +
>>> +static void kvaser_usb_unlink_all_urbs(struct kvaser_usb *dev)
>>> +{
>>> +	int i;
>>> +
>>> +	usb_kill_anchored_urbs(&dev->rx_submitted);
>>> +
>>> +	for (i = 0; i < MAX_NET_DEVICES; i++) {
>> ARRAY_SIZE()
>>> +		struct kvaser_usb_net_priv *priv = dev->nets[i];
>>> +
>>> +		if (priv)
>>> +			kvaser_usb_unlink_tx_urbs(priv);
>>> +	}
>>> +}
>>> +
>>> +static int kvaser_usb_stop_chip(struct kvaser_usb_net_priv *priv)
>>> +{
>>> +	int err;
>>> +
>>> +	init_completion(&priv->start_stop_comp);
>>> +
>>> +	err = kvaser_usb_send_simple_msg(priv->dev, CMD_STOP_CHIP,
>>> +					 priv->channel);
>>> +	if (err)
>>> +		return err;
>>> +
>>> +	if (!wait_for_completion_timeout(&priv->start_stop_comp,
>>> +					 msecs_to_jiffies(STOP_TIMEOUT)))
>>> +		return -ETIMEDOUT;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int kvaser_usb_flush_queue(struct kvaser_usb_net_priv *priv)
>>> +{
>>> +	struct kvaser_msg msg;
>>> +
>>> +	memset(&msg, 0x00, sizeof(msg));
>>> +	msg.id = CMD_FLUSH_QUEUE;
>>> +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_flush_queue);
>>> +	msg.u.flush_queue.channel = priv->channel;
>> C99 initialziers, please
> 
> Ok.
> 
>>> +
>>> +	return kvaser_usb_send_msg(priv->dev, &msg);
>>> +}
>>> +
>>> +static int kvaser_usb_close(struct net_device *netdev)
>>> +{
>>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
>>> +	int err;
>>> +
>>> +	netif_stop_queue(netdev);
>>> +
>>> +	err = kvaser_usb_flush_queue(priv);
>>> +	if (err)
>>> +		netdev_warn(netdev, "Cannot flush queue, error %d\n", err);
>>> +
>>> +	err = kvaser_usb_stop_chip(priv);
>>> +	if (err) {
>>> +		netdev_warn(netdev, "Cannot stop device, error %d\n", err);
>>> +		return err;
>>> +	}
>>> +
>>> +	kvaser_usb_unlink_tx_urbs(priv);
>>> +
>>> +	priv->can.state = CAN_STATE_STOPPED;
>>> +	close_candev(priv->netdev);
>>> +	priv->open_time = 0;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static void kvaser_usb_write_bulk_callback(struct urb *urb)
>>> +{
>>> +	struct kvaser_usb_tx_urb_context *context = urb->context;
>>> +	struct kvaser_usb_net_priv *priv;
>>> +	struct net_device *netdev;
>>> +
>>> +	if (WARN_ON(!context))
>>> +		return;
>>> +
>>> +	priv = context->priv;
>>> +	netdev = priv->netdev;
>>> +
>>> +	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
>>> +			  urb->transfer_buffer, urb->transfer_dma);
>>> +
>>> +	if (!netif_device_present(netdev))
>>> +		return;
>>> +
>>> +	if (urb->status)
>>> +		netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
>>> +
>>> +	netdev->trans_start = jiffies;
>>
>> Is trans_start needed? at least for non-usb devices it works without.
> 
> I don't know, I'll try to figure this out.
> I see it's used in the two others CAN/USB drivers, 'ems_usb.c' and
> 'esd_usb2.c'
> 
>>
>>> +}
>>> +
>>> +static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
>>> +					 struct net_device *netdev)
>>> +{
>>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
>>> +	struct kvaser_usb *dev = priv->dev;
>>> +	struct net_device_stats *stats = &netdev->stats;
>>> +	struct can_frame *cf = (struct can_frame *)skb->data;
>>> +	struct kvaser_usb_tx_urb_context *context = NULL;
>>> +	struct urb *urb;
>>> +	void *buf;
>>> +	struct kvaser_msg *msg;
>>> +	int i, err;
>>> +	int ret = NETDEV_TX_OK;
>>> +
>>> +	if (can_dropped_invalid_skb(netdev, skb))
>>> +		return NETDEV_TX_OK;
>>> +
>>> +	urb = usb_alloc_urb(0, GFP_ATOMIC);
>>> +	if (!urb) {
>>> +		netdev_err(netdev, "No memory left for URBs\n");
>>> +		stats->tx_dropped++;
>>> +		dev_kfree_skb(skb);
>>> +		goto nourbmem;
>>> +	}
>>> +
>>> +	buf = usb_alloc_coherent(dev->udev, sizeof(struct kvaser_msg),
>>> +				 GFP_ATOMIC, &urb->transfer_dma);
>>> +	if (!buf) {
>>> +		netdev_err(netdev, "No memory left for USB buffer\n");
>>> +		stats->tx_dropped++;
>>> +		dev_kfree_skb(skb);
>>> +		goto nobufmem;
>>> +	}
>>> +
>>> +	msg = (struct kvaser_msg *)buf;
>>> +	msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_tx_can);
>>> +	msg->u.tx_can.flags = 0;
>>> +	msg->u.tx_can.channel = priv->channel;
>>> +
>>> +	if (cf->can_id & CAN_EFF_FLAG) {
>>> +		msg->id = CMD_TX_EXT_MESSAGE;
>>> +		msg->u.tx_can.msg[0] = (cf->can_id >> 24) & 0x1f;
>>> +		msg->u.tx_can.msg[1] = (cf->can_id >> 18) & 0x3f;
>>> +		msg->u.tx_can.msg[2] = (cf->can_id >> 14) & 0x0f;
>>> +		msg->u.tx_can.msg[3] = (cf->can_id >> 6) & 0xff;
>>> +		msg->u.tx_can.msg[4] = cf->can_id & 0x3f;
>>> +	} else {
>>> +		msg->id = CMD_TX_STD_MESSAGE;
>>> +		msg->u.tx_can.msg[0] = (cf->can_id >> 6) & 0x1f;
>>> +		msg->u.tx_can.msg[1] = cf->can_id & 0x3f;
>>> +	}
>>> +
>>> +	msg->u.tx_can.msg[5] = cf->can_dlc;
>>> +	memcpy(&msg->u.tx_can.msg[6], cf->data, cf->can_dlc);
>>> +
>>> +	if (cf->can_id & CAN_RTR_FLAG)
>>> +		msg->u.tx_can.flags |= MSG_FLAG_REMOTE_FRAME;
>>> +
>>> +	for (i = 0; i < MAX_TX_URBS; i++) {
>> ARRAY_SIZE
> 
> Ok.
> 
>>> +		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
>>> +			context = &priv->tx_contexts[i];
>>> +			break;
>>> +		}
>>> +	}
>>> +
>>> +	if (!context) {
>>> +		netdev_warn(netdev, "cannot find free context\n");
>>> +		ret =  NETDEV_TX_BUSY;
>>> +		goto releasebuf;
>>> +	}
>>> +
>>> +	context->priv = priv;
>>> +	context->echo_index = i;
>>> +	context->dlc = cf->can_dlc;
>>> +
>>> +	msg->u.tx_can.tid = context->echo_index;
>>> +
>>> +	usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
>>> +			  buf, msg->len,
>>> +			  kvaser_usb_write_bulk_callback, context);
>>> +	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
>>> +	usb_anchor_urb(urb, &priv->tx_submitted);
>>> +
>>> +	can_put_echo_skb(skb, netdev, context->echo_index);
>>> +
>>> +	atomic_inc(&priv->active_tx_urbs);
>>> +
>>> +	if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
>>> +		netif_stop_queue(netdev);
>>> +
>>> +	err = usb_submit_urb(urb, GFP_ATOMIC);
>>> +	if (unlikely(err)) {
>>> +		can_free_echo_skb(netdev, context->echo_index);
>>> +
>>> +		atomic_dec(&priv->active_tx_urbs);
>>> +		usb_unanchor_urb(urb);
>>> +
>>> +		stats->tx_dropped++;
>>> +
>>> +		if (err == -ENODEV)
>>> +			netif_device_detach(netdev);
>>> +		else
>>> +			netdev_warn(netdev, "Failed tx_urb %d\n", err);
>>> +
>>> +		goto releasebuf;
>>> +	}
>>> +
>>> +	netdev->trans_start = jiffies;
>>> +
>>> +	usb_free_urb(urb);
>>> +
>>> +	return NETDEV_TX_OK;
>>> +
>>> +releasebuf:
>>> +	usb_free_coherent(dev->udev, sizeof(struct kvaser_msg),
>>> +			  buf, urb->transfer_dma);
>>> +nobufmem:
>>> +	usb_free_urb(urb);
>>> +nourbmem:
>>> +	return ret;
>>> +}
>>> +
>>> +static const struct net_device_ops kvaser_usb_netdev_ops = {
>>> +	.ndo_open = kvaser_usb_open,
>>> +	.ndo_stop = kvaser_usb_close,
>>> +	.ndo_start_xmit = kvaser_usb_start_xmit,
>>> +};
>>> +
>>> +static struct can_bittiming_const kvaser_usb_bittiming_const = {
>>> +	.name = "kvaser_usb",
>>> +	.tseg1_min = KVASER_USB_TSEG1_MIN,
>>> +	.tseg1_max = KVASER_USB_TSEG1_MAX,
>>> +	.tseg2_min = KVASER_USB_TSEG2_MIN,
>>> +	.tseg2_max = KVASER_USB_TSEG2_MAX,
>>> +	.sjw_max = KVASER_USB_SJW_MAX,
>>> +	.brp_min = KVASER_USB_BRP_MIN,
>>> +	.brp_max = KVASER_USB_BRP_MAX,
>>> +	.brp_inc = KVASER_USB_BRP_INC,
>>> +};
>>> +
>>> +static int kvaser_usb_set_bittiming(struct net_device *netdev)
>>> +{
>>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
>>> +	struct can_bittiming *bt = &priv->can.bittiming;
>>> +	struct kvaser_usb *dev = priv->dev;
>>> +	struct kvaser_msg msg;
>>> +
>>> +	msg.id = CMD_SET_BUS_PARAMS;
>>> +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_busparams);
>>> +	msg.u.busparams.channel = priv->channel;
>>> +	msg.u.busparams.tid = 0xff;
>>> +	msg.u.busparams.bitrate = bt->bitrate;
>>
>> bitrate is le32
> 
> Indeed ! I'll fix this.
> 
>>
>>> +	msg.u.busparams.sjw = bt->sjw;
>>> +	msg.u.busparams.tseg1 = bt->prop_seg + bt->phase_seg1;
>>> +	msg.u.busparams.tseg2 = bt->phase_seg2;
>>
>> C99 initializers, please
>>
>>> +
>>> +	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
>>> +		msg.u.busparams.no_samp = 3;
>>> +	else
>>> +		msg.u.busparams.no_samp = 1;
>>> +
>>> +	return kvaser_usb_send_msg(dev, &msg);
>>> +}
>>> +
>>> +static int kvaser_usb_set_mode(struct net_device *netdev,
>>> +			       enum can_mode mode)
>>> +{
>>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
>>> +
>>> +	if (!priv->open_time)
>>> +		return -EINVAL;
>>> +
>>> +	switch (mode) {
>>> +	case CAN_MODE_START:
>>> +		if (netif_queue_stopped(netdev))
>>> +			netif_wake_queue(netdev);
>>
>> No need to restart your USB device?
> 
> No. I don't think so.
> The module continuously tries to transmit the frame and isn't stopped.
> So there is no need to restart it if it has been explicitely stopped.
> 
> When it cannot transmit, the module try again and sends continuously
> CMD_CAN_ERROR_EVENT frames until it succeeds to transmit the frame.
> If the device is stopped with the command CMD_STOP_CHIP then it stops
> sending these CMD_CAN_ERROR_EVENT.
> Should I handle this in another manner?

If the firmware automatically recovers from busoff (like the at91 does),
you should stop the chip it priv->can.restart_ms == 0 and let the chip
continue working otherwise.

> 
>>
>>> +		break;
>>> +	default:
>>> +		return -EOPNOTSUPP;
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int kvaser_usb_get_berr_counter(const struct net_device *netdev,
>>> +				       struct can_berr_counter *bec)
>>> +{
>>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
>>> +
>>> +	bec->txerr = priv->bec.txerr;
>>> +	bec->rxerr = priv->bec.rxerr;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int kvaser_usb_init_one(struct usb_interface *intf,
>>> +			       const struct usb_device_id *id, int channel)
>>> +{
>>> +	struct kvaser_usb *dev = usb_get_intfdata(intf);
>>> +	struct net_device *netdev;
>>> +	struct kvaser_usb_net_priv *priv;
>>> +	int i, err;
>>> +
>>> +	netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
>>> +	if (!netdev) {
>>> +		dev_err(&intf->dev, "Cannot alloc candev\n");
>>> +		return -ENOMEM;
>>> +	}
>>> +
>>> +	priv = netdev_priv(netdev);
>>> +
>>> +	init_usb_anchor(&priv->tx_submitted);
>>> +	atomic_set(&priv->active_tx_urbs, 0);
>>> +
>>> +	for (i = 0; i < MAX_TX_URBS; i++)
>>> +		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
>>> +
>>> +	priv->dev = dev;
>>> +	priv->netdev = netdev;
>>> +	priv->channel = channel;
>>> +
>>> +	priv->can.state = CAN_STATE_STOPPED;
>>> +	priv->can.clock.freq = CAN_USB_CLOCK;
>>> +	priv->can.bittiming_const = &kvaser_usb_bittiming_const;
>>> +	priv->can.do_set_bittiming = kvaser_usb_set_bittiming;
>>> +	priv->can.do_set_mode = kvaser_usb_set_mode;
>>> +	priv->can.do_get_berr_counter = kvaser_usb_get_berr_counter;
>>> +	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
>>> +	if (id->driver_info & KVASER_HAS_SILENT_MODE)
>>> +		priv->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
>>> +
>>> +	netdev->flags |= IFF_ECHO;
>>> +
>>> +	netdev->netdev_ops = &kvaser_usb_netdev_ops;
>>> +
>>> +	SET_NETDEV_DEV(netdev, &intf->dev);
>>> +
>>> +	err = register_candev(netdev);
>>> +	if (err) {
>>> +		dev_err(&intf->dev, "Failed to register can device\n");
>>> +		free_candev(netdev);
>>> +		return err;
>>> +	}
>>> +
>>> +	dev->nets[channel] = priv;
>>> +	netdev_info(netdev, "device %s registered\n", netdev->name);
>>
>> netdev_info should take care of printing the device's name.
> 
> Ok.
> 
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int kvaser_usb_probe(struct usb_interface *intf,
>>> +			    const struct usb_device_id *id)
>>> +{
>>> +	struct kvaser_usb *dev;
>>> +	int err = -ENOMEM;
>>> +	int i;
>>> +
>>> +	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
>>
>> Who will free dev on driver unload? Please make use of devm_kzalloc().
> 
> Ok. kfree is missing is disconnect().
> I'll replace it by devm_kzalloc() and devm_free().

The beauty of devm_kzalloc is you don't have to call *_free, its
automatically called if probe fails or when remove function has been called.

> 
>>
>>> +	if (!dev)
>>> +		return -ENOMEM;
>>> +
>>> +	dev->udev = interface_to_usbdev(intf);
>>> +
>>> +	init_usb_anchor(&dev->rx_submitted);
>>> +
>>> +	usb_set_intfdata(intf, dev);
>>> +
>>> +	if (kvaser_usb_send_simple_msg(dev, CMD_RESET_CHIP, 0)) {
>>> +		dev_err(&intf->dev, "Cannot reset kvaser\n");
>>> +		goto error;
>>> +	}
>>> +
>>> +	if (kvaser_usb_get_software_info(dev)) {
>>> +		dev_err(&intf->dev, "Cannot get software infos\n");
>>> +		goto error;
>>> +	}
>>> +
>>> +	if (kvaser_usb_get_card_info(dev)) {
>>> +		dev_err(&intf->dev, "Cannot get card infos\n");
>>> +		goto error;
>>> +	}
>>> +
>>> +	dev_dbg(&intf->dev, "Firmware version: %d.%d.%d\n",
>>> +		 ((dev->fw_version >> 24) & 0xff),
>>> +		 ((dev->fw_version >> 16) & 0xff),
>>> +		 (dev->fw_version & 0xffff));
>>> +
>>> +	for (i = 0; i < dev->nchannels; i++)
>>> +		kvaser_usb_init_one(intf, id, i);
>>> +
>>> +	return 0;
>>> +
>>> +error:
>>> +	kfree(dev);
>>> +	return err;
>>> +}
>>> +
>>> +static void kvaser_usb_disconnect(struct usb_interface *intf)
>>> +{
>>> +	struct kvaser_usb *dev = usb_get_intfdata(intf);
>>> +	int i;
>>> +
>>> +	usb_set_intfdata(intf, NULL);
>>> +
>>> +	if (!dev)
>>> +		return;
>>> +
>>> +	for (i = 0; i < dev->nchannels; i++) {
>>> +		if (!dev->nets[i])
>>> +			continue;
>>> +
>>> +		unregister_netdev(dev->nets[i]->netdev);
>>> +		free_candev(dev->nets[i]->netdev);
>>> +	}
>>> +
>>> +	kvaser_usb_unlink_all_urbs(dev);
>>> +}
>>> +
>>> +static struct usb_driver kvaser_usb_driver = {
>>> +	.name = "kvaser_usb",
>>> +	.probe = kvaser_usb_probe,
>>> +	.disconnect = kvaser_usb_disconnect,
>>> +	.id_table = kvaser_usb_table
>>> +};
>>> +
>>> +module_usb_driver(kvaser_usb_driver);
>>> +
>>> +MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
>>> +MODULE_DESCRIPTION("Can driver for Kvaser CAN/USB devices");
>>> +MODULE_LICENSE("GPL v2");
>>> diff --git a/drivers/net/can/usb/kvaser_usb.h b/drivers/net/can/usb/kvaser_usb.h
>>> new file mode 100644
>>> index 0000000..8e0b6ab
>>> --- /dev/null
>>> +++ b/drivers/net/can/usb/kvaser_usb.h
>>> @@ -0,0 +1,237 @@
>>> +#ifndef _KVASER_USB_H_
>>> +#define _KVASER_USB_H_
>>> +
>>> +#define	MAX_TX_URBS			16
>> Please no tab between define and macro name
> 
> Ok I didn't know it was not allowed... checkpatch didn't complain.

It's allowed, but not used without tab it's more common, at least among
CAN drivers.

> 
>>> +#define	MAX_RX_URBS			4
>>> +#define	START_TIMEOUT			1000
>>> +#define	STOP_TIMEOUT			1000
>>> +#define	USB_SEND_TIMEOUT		1000
>>> +#define	USB_RECEIVE_TIMEOUT		1000
>>> +#define	RX_BUFFER_SIZE			3072
>>> +#define	CAN_USB_CLOCK			8000000
>>> +#define	MAX_NET_DEVICES			3
>>> +
>>> +/* Kvaser USB devices */
>>> +#define	KVASER_VENDOR_ID		0x0bfd
>>> +#define	USB_LEAF_DEVEL_PRODUCT_ID	10
>>> +#define	USB_LEAF_LITE_PRODUCT_ID	11
>>> +#define	USB_LEAF_PRO_PRODUCT_ID		12
>>> +#define	USB_LEAF_SPRO_PRODUCT_ID	14
>>> +#define	USB_LEAF_PRO_LS_PRODUCT_ID	15
>>> +#define	USB_LEAF_PRO_SWC_PRODUCT_ID	16
>>> +#define	USB_LEAF_PRO_LIN_PRODUCT_ID	17
>>> +#define	USB_LEAF_SPRO_LS_PRODUCT_ID	18
>>> +#define	USB_LEAF_SPRO_SWC_PRODUCT_ID	19
>>> +#define	USB_MEMO2_DEVEL_PRODUCT_ID	22
>>> +#define	USB_MEMO2_HSHS_PRODUCT_ID	23
>>> +#define	USB_UPRO_HSHS_PRODUCT_ID	24
>>> +#define	USB_LEAF_LITE_GI_PRODUCT_ID	25
>>> +#define	USB_LEAF_PRO_OBDII_PRODUCT_ID	26
>>> +#define	USB_MEMO2_HSLS_PRODUCT_ID	27
>>> +#define	USB_LEAF_LITE_CH_PRODUCT_ID	28
>>> +#define	USB_BLACKBIRD_SPRO_PRODUCT_ID	29
>>> +#define	USB_OEM_MERCURY_PRODUCT_ID	34
>>> +#define	USB_OEM_LEAF_PRODUCT_ID		35
>>> +#define	USB_CAN_R_PRODUCT_ID		39
>>> +
>>> +/* USB devices features */
>>> +#define	KVASER_HAS_SILENT_MODE		(1 << 0)
>> pleae use BIT(0)
>>> +
>>> +/* Message header size */
>>> +#define	MSG_HEADER_LEN			2
>>> +
>>> +/* Can message flags */
>>> +#define	MSG_FLAG_ERROR_FRAME		(1 << 0)
>>> +#define	MSG_FLAG_OVERRUN		(1 << 1)
>>> +#define	MSG_FLAG_NERR			(1 << 2)
>>> +#define	MSG_FLAG_WAKEUP			(1 << 3)
>>> +#define	MSG_FLAG_REMOTE_FRAME		(1 << 4)
>>> +#define	MSG_FLAG_RESERVED		(1 << 5)
>>> +#define	MSG_FLAG_TX_ACK			(1 << 6)
>>> +#define	MSG_FLAG_TX_REQUEST		(1 << 7)
>>> +
>>> +/* Can states */
>>> +#define	M16C_STATE_BUS_RESET		(1 << 0)
>>> +#define	M16C_STATE_BUS_ERROR		(1 << 4)
>>> +#define	M16C_STATE_BUS_PASSIVE		(1 << 5)
>>> +#define	M16C_STATE_BUS_OFF		(1 << 6)
>>> +
>>> +/* Can msg ids */
>>> +#define	CMD_RX_STD_MESSAGE		12
>>> +#define	CMD_TX_STD_MESSAGE		13
>>> +#define	CMD_RX_EXT_MESSAGE		14
>>> +#define	CMD_TX_EXT_MESSAGE		15
>>> +#define	CMD_SET_BUS_PARAMS		16
>>> +#define	CMD_GET_BUS_PARAMS		17
>>> +#define	CMD_GET_BUS_PARAMS_REPLY	18
>>> +#define	CMD_GET_CHIP_STATE		19
>>> +#define	CMD_CHIP_STATE_EVENT		20
>>> +#define	CMD_SET_CTRL_MODE		21
>>> +#define	CMD_GET_CTRL_MODE		22
>>> +#define	CMD_GET_CTRL_MODE_REPLY		23
>>> +#define	CMD_RESET_CHIP			24
>>> +#define	CMD_RESET_CHIP_REPLY		25
>>> +#define	CMD_START_CHIP			26
>>> +#define	CMD_START_CHIP_REPLY		27
>>> +#define	CMD_STOP_CHIP			28
>>> +#define	CMD_STOP_CHIP_REPLY		29
>>> +#define	CMD_GET_CARD_INFO2		32
>>> +#define	CMD_GET_CARD_INFO		34
>>> +#define	CMD_GET_CARD_INFO_REPLY		35
>>> +#define	CMD_GET_SOFTWARE_INFO		38
>>> +#define	CMD_GET_SOFTWARE_INFO_REPLY	39
>>> +#define	CMD_ERROR_EVENT			45
>>> +#define	CMD_FLUSH_QUEUE			48
>>> +#define	CMD_TX_ACKNOWLEDGE		50
>>> +#define	CMD_CAN_ERROR_EVENT		51
>>> +#define	CMD_USB_THROTTLE		77
>>> +
>>> +/* error factors */
>>> +#define	M16C_EF_ACKE			(1 << 0)
>>> +#define	M16C_EF_CRCE			(1 << 1)
>>> +#define	M16C_EF_FORME			(1 << 2)
>>> +#define	M16C_EF_STFE			(1 << 3)
>>> +#define	M16C_EF_BITE0			(1 << 4)
>>> +#define	M16C_EF_BITE1			(1 << 5)
>>> +#define	M16C_EF_RCVE			(1 << 6)
>>> +#define	M16C_EF_TRE			(1 << 7)
>>> +
>>> +/* bittiming parameters */
>>> +#define	KVASER_USB_TSEG1_MIN		1
>>> +#define	KVASER_USB_TSEG1_MAX		16
>>> +#define	KVASER_USB_TSEG2_MIN		1
>>> +#define	KVASER_USB_TSEG2_MAX		8
>>> +#define	KVASER_USB_SJW_MAX		4
>>> +#define	KVASER_USB_BRP_MIN		1
>>> +#define	KVASER_USB_BRP_MAX		64
>>> +#define	KVASER_USB_BRP_INC		1
>>> +
>>> +/* ctrl modes */
>>> +#define	KVASER_CTRL_MODE_NORMAL		1
>>> +#define	KVASER_CTRL_MODE_SILENT		2
>>> +#define	KVASER_CTRL_MODE_SELFRECEPTION	3
>>> +#define	KVASER_CTRL_MODE_OFF		4
>>> +
>>> +struct kvaser_msg_simple {
>>> +	u8 tid;
>>> +	u8 channel;
>>> +} __packed;
>>> +
>>> +struct kvaser_msg_cardinfo {
>>> +	u8 tid;
>>> +	u8 nchannels;
>>> +	__le32 serial_number;
>>> +	__le32 padding;
>>> +	__le32 clock_resolution;
>>> +	__le32 mfgdate;
>>> +	u8 ean[8];
>>> +	u8 hw_revision;
>>> +	u8 usb_hs_mode;
>>> +	__le16 padding2;
>>> +} __packed;
>>> +
>>> +struct kvaser_msg_cardinfo2 {
>>> +	u8 tid;
>>> +	u8 channel;
>>> +	u8 pcb_id[24];
>>> +	__le32 oem_unlock_code;
>>> +} __packed;
>>> +
>>> +struct kvaser_msg_softinfo {
>>> +	u8 tid;
>>> +	u8 channel;
>>> +	__le32 sw_options;
>>> +	__le32 fw_version;
>>> +	__le16 max_outstanding_tx;
>>> +	__le16 padding[9];
>>> +} __packed;
>>> +
>>> +struct kvaser_msg_busparams {
>>> +	u8 tid;
>>> +	u8 channel;
>>> +	__le32 bitrate;
>>> +	u8 tseg1;
>>> +	u8 tseg2;
>>> +	u8 sjw;
>>> +	u8 no_samp;
>>> +} __packed;
>>> +
>>> +struct kvaser_msg_tx_can {
>>> +	u8 channel;
>>> +	u8 tid;
>>> +	u8 msg[14];
>>> +	u8 padding;
>>> +	u8 flags;
>>> +} __packed;
>>> +
>>> +struct kvaser_msg_rx_can {
>>> +	u8 channel;
>>> +	u8 flag;
>>> +	__le16 time[3];
>>> +	u8 msg[14];
>>> +} __packed;
>>> +
>>> +struct kvaser_msg_chip_state_event {
>>> +	u8 tid;
>>> +	u8 channel;
>>> +	__le16 time[3];
>>> +	u8 tx_errors_count;
>>> +	u8 rx_errors_count;
>>> +	u8 status;
>>> +	u8 padding[3];
>>> +} __packed;
>>> +
>>> +struct kvaser_msg_tx_acknowledge {
>>> +	u8 channel;
>>> +	u8 tid;
>>> +	__le16 time[3];
>>> +	u8 flags;
>>> +	u8 time_offset;
>>> +} __packed;
>>> +
>>> +struct kvaser_msg_error_event {
>>> +	u8 tid;
>>> +	u8 flags;
>>> +	__le16 time[3];
>>> +	u8 channel;
>>> +	u8 padding;
>>> +	u8 tx_errors_count;
>>> +	u8 rx_errors_count;
>>> +	u8 status;
>>> +	u8 error_factor;
>>> +} __packed;
>>> +
>>> +struct kvaser_msg_ctrl_mode {
>>> +	u8 tid;
>>> +	u8 channel;
>>> +	u8 ctrl_mode;
>>> +	u8 padding[3];
>>> +} __packed;
>>> +
>>> +struct kvaser_msg_flush_queue {
>>> +	u8 tid;
>>> +	u8 channel;
>>> +	u8 flags;
>>> +	u8 padding[3];
>>> +} __packed;
>>> +
>>> +struct kvaser_msg {
>>> +	u8 len;
>>> +	u8 id;
>>> +	union	{
>>> +		struct kvaser_msg_simple simple;
>>> +		struct kvaser_msg_cardinfo cardinfo;
>>> +		struct kvaser_msg_cardinfo2 cardinfo2;
>>> +		struct kvaser_msg_softinfo softinfo;
>>> +		struct kvaser_msg_busparams busparams;
>>> +		struct kvaser_msg_tx_can tx_can;
>>> +		struct kvaser_msg_rx_can rx_can;
>>> +		struct kvaser_msg_chip_state_event chip_state_event;
>>> +		struct kvaser_msg_tx_acknowledge tx_acknowledge;
>>> +		struct kvaser_msg_error_event error_event;
>>> +		struct kvaser_msg_ctrl_mode ctrl_mode;
>>> +		struct kvaser_msg_ctrl_mode flush_queue;
>>> +	} u;
>>> +} __packed;
>>> +
>>> +#endif
>>>
>>
>>
>> -- 
>> Pengutronix e.K.                  | Marc Kleine-Budde           |
>> Industrial Linux Solutions        | Phone: +49-231-2826-924     |
>> Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
>> Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |
>>
> 
> Thanks for the review.
np,

regards, Marc

On Tue, Jul 31, 2012 at 11:56:22AM +0200, Marc Kleine-Budde wrote:
> On 07/30/2012 03:33 PM, Olivier Sobrie wrote:
> > Hi Marc,
> > 
> > On Mon, Jul 30, 2012 at 01:11:46PM +0200, Marc Kleine-Budde wrote:
> >> On 07/30/2012 07:32 AM, Olivier Sobrie wrote:
> >>> This driver provides support for several Kvaser CAN/USB devices.
> >>> Such kind of devices supports up to three can network interfaces.
> >>>
> >>> It has been tested with a Kvaser USB Leaf Light (one network interface)
> >>> connected to a pch_can interface.
> >>> The firmware version of the Kvaser device was 2.5.205.
> >>
> >> Please add linux-usb@vger.kernel.org to Cc for review of the USB part.
> > 
> > Ok I'll do it when I send the new version of the patch.
> > But it might be a good idea to add an entry in the MAINTAINERS file so
> > that when someone sends a patch they are aware of this when the
> > get_maintainer script is invoked.
> 
> Interesting Idea. We should discuss this here, however we should not
> bother the USB List when sending USB unrelated patches.
> 
> >> Please combine .h and .c file. Please make use of netdev_LEVEL() for
> >> error printing, not dev_LEVEL().
> > 
> > I'll combine the .c and .h.
> > I used the netdev_LEVEL() everywhere it was possible. It requires to
> > have access to a pointer to netdev which is not always possible;
> > that's the reason why I used dev_LEVEL().
> 
> I see, you used it when channel is invalid. So you have obviously no netdev.

Indeed.

> 
> >> Please review if all members of the struct kvaser_msg are properly
> >> aligned. You never access the struct kvaser_msg_* members directly, as
> >> they are unaligned. Please check for le16 and le32 access. You missed to
> >> convert the bitrate.
> > 
> > Indeed. Thanks. I'll check if I didn't missed another one.
> 
> Tnx
> 
> >> Please check if your driver survives hot-unplugging while sending and
> >> receiving CAN frames at maximum laod.
> > 
> > I tested this with two Kvaser sending frames with "cangen can0 -g 0 -i"
> > never saw a crash.
> 
> Please test send sending and receiving at the same time.

Yes that's what I did; "cangen can0 -g 0 -i" on both sides.

> 
> >> More comments inline,
> >> regards, Marc
> >>
> >>> List of Kvaser devices supported by the driver:
> >>>   - Kvaser Leaf prototype (P010v2 and v3)
> >>>   - Kvaser Leaf Light (P010v3)
> >>>   - Kvaser Leaf Professional HS
> >>>   - Kvaser Leaf SemiPro HS
> >>>   - Kvaser Leaf Professional LS
> >>>   - Kvaser Leaf Professional SWC
> >>>   - Kvaser Leaf Professional LIN
> >>>   - Kvaser Leaf SemiPro LS
> >>>   - Kvaser Leaf SemiPro SWC
> >>>   - Kvaser Memorator II, Prototype
> >>>   - Kvaser Memorator II HS/HS
> >>>   - Kvaser USBcan Professional HS/HS
> >>>   - Kvaser Leaf Light GI
> >>>   - Kvaser Leaf Professional HS (OBD-II connector)
> >>>   - Kvaser Memorator Professional HS/LS
> >>>   - Kvaser Leaf Light "China"
> >>>   - Kvaser BlackBird SemiPro
> >>>   - Kvaser OEM Mercury
> >>>   - Kvaser OEM Leaf
> >>>   - Kvaser USBcan R
> >>>
> >>> Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
> >>> ---
> >>>  drivers/net/can/usb/Kconfig      |   33 ++
> >>>  drivers/net/can/usb/Makefile     |    1 +
> >>>  drivers/net/can/usb/kvaser_usb.c | 1062 ++++++++++++++++++++++++++++++++++++++
> >>>  drivers/net/can/usb/kvaser_usb.h |  237 +++++++++
> >>>  4 files changed, 1333 insertions(+)
> >>>  create mode 100644 drivers/net/can/usb/kvaser_usb.c
> >>>  create mode 100644 drivers/net/can/usb/kvaser_usb.h
> >>>
> >>> diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
> >>> index 0a68768..578955f 100644
> >>> --- a/drivers/net/can/usb/Kconfig
> >>> +++ b/drivers/net/can/usb/Kconfig
> >>> @@ -13,6 +13,39 @@ config CAN_ESD_USB2
> >>>            This driver supports the CAN-USB/2 interface
> >>>            from esd electronic system design gmbh (http://www.esd.eu).
> >>>  
> >>> +config CAN_KVASER_USB
> >>> +	tristate "Kvaser CAN/USB interface"
> >>> +	---help---
> >>> +	  This driver adds support for Kvaser CAN/USB devices like Kvaser
> >>> +	  Leaf Light.
> >>> +
> >>> +	  The driver gives support for the following devices:
> >>> +	    - Kvaser Leaf prototype (P010v2 and v3)
> >>> +	    - Kvaser Leaf Light (P010v3)
> >>> +	    - Kvaser Leaf Professional HS
> >>> +	    - Kvaser Leaf SemiPro HS
> >>> +	    - Kvaser Leaf Professional LS
> >>> +	    - Kvaser Leaf Professional SWC
> >>> +	    - Kvaser Leaf Professional LIN
> >>> +	    - Kvaser Leaf SemiPro LS
> >>> +	    - Kvaser Leaf SemiPro SWC
> >>> +	    - Kvaser Memorator II, Prototype
> >>> +	    - Kvaser Memorator II HS/HS
> >>> +	    - Kvaser USBcan Professional HS/HS
> >>> +	    - Kvaser Leaf Light GI
> >>> +	    - Kvaser Leaf Professional HS (OBD-II connector)
> >>> +	    - Kvaser Memorator Professional HS/LS
> >>> +	    - Kvaser Leaf Light "China"
> >>> +	    - Kvaser BlackBird SemiPro
> >>> +	    - Kvaser OEM Mercury
> >>> +	    - Kvaser OEM Leaf
> >>> +	    - Kvaser USBcan R
> >>> +
> >>> +	  If unsure, say N.
> >>> +
> >>> +	  To compile this driver as a module, choose M here: the
> >>> +	  module will be called kvaser_usb.
> >>> +
> >>>  config CAN_PEAK_USB
> >>>  	tristate "PEAK PCAN-USB/USB Pro interfaces"
> >>>  	---help---
> >>> diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
> >>> index da6d1d3..80a2ee4 100644
> >>> --- a/drivers/net/can/usb/Makefile
> >>> +++ b/drivers/net/can/usb/Makefile
> >>> @@ -4,6 +4,7 @@
> >>>  
> >>>  obj-$(CONFIG_CAN_EMS_USB) += ems_usb.o
> >>>  obj-$(CONFIG_CAN_ESD_USB2) += esd_usb2.o
> >>> +obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o
> >>>  obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
> >>>  
> >>>  ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
> >>> diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
> >>> new file mode 100644
> >>> index 0000000..4965480
> >>> --- /dev/null
> >>> +++ b/drivers/net/can/usb/kvaser_usb.c
> >>> @@ -0,0 +1,1062 @@
> >>> +/*
> >>
> >> Please add a license statement and probably your copyright:
> >>
> >>  * This program is free software; you can redistribute it and/or
> >>  * modify it under the terms of the GNU General Public License as
> >>  * published by the Free Software Foundation version 2.
> >>
> >> You also should copy the copyright from the drivers you used:
> >>
> >>> + * Parts of this driver are based on the following:
> >>> + *  - Kvaser linux leaf driver (version 4.78)
> >>
> >> I just downloaded their driver and noticed that it's quite sparse on
> >> stating the license the code is released under.
> >> "doc/HTMLhelp/copyright.htx" is quite restrictive, the word GPL occurs 3
> >> times, all in MODULE_LICENSE("GPL"). Running modinfo on the usbcan.ko
> >> shows "license: GPL"
> > 
> > I'll add the license statement.
> > In fact it's the leaf.ko which is used for this device and it is under
> > GPL as modinfo said.
> 
> I just talked to my boss and we're the same opinion, that
> MODULE_LICENSE("GPL") is a technical term and not relevant if the
> included license doesn't say a word about GPL. If the kvaser tarball
> violates the GPL, however is written on different sheet of paper (as we
> say in Germany).
> 
> So I cannot put my S-o-b under this driver as long as we haven't talked
> to kvaser.

Ok I thought it was sufficient enough to have MODULE_LICENSE("GPL") in
the code to indicate it is a GPL driver. I'll ask Kvaser before sending
any new version of the patch.

> 
> >>> + *  - CAN driver for esd CAN-USB/2
> >>> + */
> >>> +
> >>> +#include <linux/init.h>
> >>> +#include <linux/completion.h>
> >>> +#include <linux/module.h>
> >>> +#include <linux/netdevice.h>
> >>> +#include <linux/usb.h>
> >>> +
> >>> +#include <linux/can.h>
> >>> +#include <linux/can/dev.h>
> >>> +#include <linux/can/error.h>
> >>> +
> >>> +#include "kvaser_usb.h"
> >>> +
> >>> +struct kvaser_usb_tx_urb_context {
> >>> +	struct kvaser_usb_net_priv *priv;
> >>
> >> Huh - how does this work without forward declaration?
> > 
> > It works.
> 
> Yes, obviously :)
> 
> > "In C and C++ it is possible to declare pointers to structs before
> > declaring their struct layout, provided the pointers are not
> > dereferenced--this is known as forward declaration."
> > 
> > See http://www.linuxtopia.org/online_books/an_introduction_to_gcc/gccintro_94.html
> 
> Thanks for the link.
> >>
> >>> +	u32 echo_index;
> >>> +	int dlc;
> >>> +};
> >>> +
> >>> +struct kvaser_usb {
> >>> +	struct usb_device *udev;
> >>> +	struct kvaser_usb_net_priv *nets[MAX_NET_DEVICES];
> >>> +
> >>> +	struct usb_anchor rx_submitted;
> >>> +
> >>> +	u32 fw_version;
> >>> +	unsigned int nchannels;
> >>> +
> >>> +	bool rxinitdone;
> >>> +};
> >>> +
> >>> +struct kvaser_usb_net_priv {
> >>> +	struct can_priv can;
> >>> +
> >>> +	atomic_t active_tx_urbs;
> >>> +	struct usb_anchor tx_submitted;
> >>> +	struct kvaser_usb_tx_urb_context tx_contexts[MAX_TX_URBS];
> >>> +
> >>> +	int open_time;
> >>
> >> please remove open_time
> > 
> > Ok.
> > 
> >>
> >>> +	struct completion start_stop_comp;
> >>> +
> >>> +	struct kvaser_usb *dev;
> >>> +	struct net_device *netdev;
> >>> +	int channel;
> >>> +	struct can_berr_counter bec;
> >>> +};
> >>> +
> >>> +static struct usb_device_id kvaser_usb_table[] = {
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_DEVEL_PRODUCT_ID) },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_PRODUCT_ID) },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_PRODUCT_ID),
> >>> +		.driver_info = KVASER_HAS_SILENT_MODE },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_PRODUCT_ID),
> >>> +		.driver_info = KVASER_HAS_SILENT_MODE },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_LS_PRODUCT_ID),
> >>> +		.driver_info = KVASER_HAS_SILENT_MODE },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_SWC_PRODUCT_ID),
> >>> +		.driver_info = KVASER_HAS_SILENT_MODE },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_LIN_PRODUCT_ID),
> >>> +		.driver_info = KVASER_HAS_SILENT_MODE },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_LS_PRODUCT_ID),
> >>> +		.driver_info = KVASER_HAS_SILENT_MODE },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_SWC_PRODUCT_ID),
> >>> +		.driver_info = KVASER_HAS_SILENT_MODE },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_DEVEL_PRODUCT_ID),
> >>> +		.driver_info = KVASER_HAS_SILENT_MODE },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_HSHS_PRODUCT_ID),
> >>> +		.driver_info = KVASER_HAS_SILENT_MODE },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_UPRO_HSHS_PRODUCT_ID) },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_GI_PRODUCT_ID) },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_OBDII_PRODUCT_ID),
> >>> +		.driver_info = KVASER_HAS_SILENT_MODE },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_HSLS_PRODUCT_ID) },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_CH_PRODUCT_ID) },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_BLACKBIRD_SPRO_PRODUCT_ID) },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_OEM_MERCURY_PRODUCT_ID) },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_OEM_LEAF_PRODUCT_ID) },
> >>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_CAN_R_PRODUCT_ID) },
> >>> +	{ }
> >>> +};
> >>> +MODULE_DEVICE_TABLE(usb, kvaser_usb_table);
> >>> +
> >>> +static int kvaser_usb_send_msg(const struct kvaser_usb *dev,
> >>> +			       struct kvaser_msg *msg)
> >> inline?
> > 
> > Ok.
> > 
> >>> +{
> >>> +	int actual_len;
> >>> +
> >>> +	return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 1),
> >>                                                                   ^
> >> Can you please introduce a #define for this.
> > 
> > Ok. No problem.
> > 
> >>
> >>> +			    msg, msg->len, &actual_len, USB_SEND_TIMEOUT);
> >>> +}
> >>> +
> >>> +static int kvaser_usb_wait_msg(const struct kvaser_usb *dev, u8 id,
> >>> +			       struct kvaser_msg *msg)
> >>> +{
> >>> +	struct kvaser_msg *tmp;
> >>> +	void *buf;
> >>> +	int actual_len;
> >>> +	int err;
> >>> +	int pos = 0;
> >>> +
> >>> +	buf = kzalloc(RX_BUFFER_SIZE, GFP_KERNEL);
> >>> +	if (!buf)
> >>> +		return -ENOMEM;
> >>> +
> >>> +	err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, 129),
> >>                                                                  ^^^
> >> dito
> > 
> > Ok too.
> > 
> >>
> >>> +			   buf, RX_BUFFER_SIZE, &actual_len,
> >>> +			   USB_RECEIVE_TIMEOUT);
> >>> +	if (err < 0) {
> >>> +		kfree(buf);
> >>> +		return err;
> >>> +	}
> >>> +
> >>> +	while (pos < actual_len) {
> >>
> >> Please check that pos + sizeof(*msg) is < actual_len, as you fill access
> >> it later.
> > 
> > I'll instead perform a check on 'pos + tmp->len < actual_len' and copy
> > only tmp->len instead of sizeof(*msg).
> > Thanks.
> 
> Even better, saves some bytes to be copied. Take care not to deref tmp,
> unless you checked that tmp is in valid memory.

Ok. I changed the loop by 'while (pos <= actual_len - MSG_HEADER_LEN)'
and then perform the check on 'pos + tmp->len < actual_len'.

> 
> >>
> >>> +		tmp = buf + pos;
> >>> +
> >>> +		if (!tmp->len)
> >>> +			break;
> >>> +
> >>> +		if (tmp->id == id) {
> >>> +			memcpy(msg, tmp, sizeof(*msg));
> >>> +			kfree(buf);
> >>> +			return 0;
> >>> +		}
> >>> +
> >>> +		pos += tmp->len;
> >>> +	}
> >>> +
> >>> +	kfree(buf);
> >>> +
> >>> +	return -EINVAL;
> >>> +}
> >>> +
> >>> +static int kvaser_usb_send_simple_msg(const struct kvaser_usb *dev,
> >>> +				      u8 msg_id, int channel)
> >>> +{
> >>> +	struct kvaser_msg msg;
> >>> +	int err;
> >>> +
> >>> +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_simple);
> >>> +	msg.id = msg_id;
> >>> +	msg.u.simple.channel = channel;
> >>> +	msg.u.simple.tid = 0xff;
> >>
> >> Please use C99 struct initializer.
> >>
> >> struct kvaser_msg msg = {
> >> 	.len = ,
> >> 	.id =,
> >> };
> > 
> > Ok.
> > 
> >>
> >>
> >>> +
> >>> +	err = kvaser_usb_send_msg(dev, &msg);
> >>
> >> 	just:
> >> 	return err;
> > 
> > Ok.
> > 
> >>
> >>> +	if (err)
> >>> +		return err;
> >>> +
> >>> +	return 0;
> >>> +}
> >>> +
> >>> +static int kvaser_usb_get_software_info(struct kvaser_usb *dev)
> >>> +{
> >>> +	struct kvaser_msg msg;
> >>> +	int err;
> >>> +
> >>> +	err = kvaser_usb_send_simple_msg(dev, CMD_GET_SOFTWARE_INFO, 0);
> >>> +	if (err)
> >>> +		return err;
> >>> +
> >>> +	err = kvaser_usb_wait_msg(dev, CMD_GET_SOFTWARE_INFO_REPLY, &msg);
> >>> +	if (err)
> >>> +		return err;
> >>> +
> >>> +	dev->fw_version = le32_to_cpu(msg.u.softinfo.fw_version);
> >>> +
> >>> +	return 0;
> >>> +}
> >>> +
> >>> +static int kvaser_usb_get_card_info(struct kvaser_usb *dev)
> >>> +{
> >>> +	struct kvaser_msg msg;
> >>> +	int err;
> >>> +
> >>> +	err = kvaser_usb_send_simple_msg(dev, CMD_GET_CARD_INFO, 0);
> >>> +	if (err)
> >>> +		return err;
> >>> +
> >>> +	err = kvaser_usb_wait_msg(dev, CMD_GET_CARD_INFO_REPLY, &msg);
> >>> +	if (err)
> >>> +		return err;
> >>> +
> >>> +	dev->nchannels = msg.u.cardinfo.nchannels;
> >>> +
> >>> +	return 0;
> >>> +}
> >>> +
> >>> +static void kvaser_usb_tx_acknowledge(const struct kvaser_usb *dev,
> >>> +				      const struct kvaser_msg *msg)
> >>> +{
> >>> +	struct net_device_stats *stats;
> >>> +	struct kvaser_usb_tx_urb_context *context;
> >>> +	struct kvaser_usb_net_priv *priv;
> >>> +	u8 channel = msg->u.tx_acknowledge.channel;
> >>> +	u8 tid = msg->u.tx_acknowledge.tid;
> >>> +
> >>> +	if (channel >= dev->nchannels) {
> >>> +		dev_err(dev->udev->dev.parent,
> >>> +			"Invalid channel number (%d)\n", channel);
> >>> +		return;
> >>> +	}
> >>
> >> can you do a check for (channel >= dev->nchannels), in a central place?
> >> e.g. kvaser_usb_handle_message()?
> > 
> > The problem is that channel is not always at the same place in the
> > messages I get from the hardware. 'tid' and 'channel' are inverted for
> > tx and rx frames.
> > e.g.
> 
> Grr...who's written that firmware :D
> 
> > 
> > struct kvaser_msg_tx_can {
> >         u8 channel;
> >         u8 tid;
> >         u8 msg[14];
> >         u8 padding;
> >         u8 flags;
> > } __packed;
> > 
> > struct kvaser_msg_busparams {
> >         u8 tid;
> >         u8 channel;
> >         __le32 bitrate;
> >         u8 tseg1;
> >         u8 tseg2;
> >         u8 sjw;
> >         u8 no_samp;
> > } __packed;
> > 
> >>
> >>> +
> >>> +	priv = dev->nets[channel];
> >>> +
> >>> +	if (!netif_device_present(priv->netdev))
> >>> +		return;
> >>> +
> >>> +	stats = &priv->netdev->stats;
> >>> +
> >>> +	context = &priv->tx_contexts[tid % MAX_TX_URBS];
> >>> +
> >>> +	/*
> >>> +	 * It looks like the firmware never sets the flags field of the
> >>> +	 * tx_acknowledge frame and never reports a transmit failure.
> >>> +	 * If the can message can't be transmited (e.g. incompatible
> >>> +	 * bitrates), a frame CMD_CAN_ERROR_EVENT is sent (with a null
> >>> +	 * tid) and the firmware tries to transmit again the packet until
> >>> +	 * it succeeds. Once the packet is successfully transmitted, then
> >>> +	 * the tx_acknowledge frame is sent.
> >>> +	 */
> >>> +
> >>> +	stats->tx_packets++;
> >>> +	stats->tx_bytes += context->dlc;
> >>> +	can_get_echo_skb(priv->netdev, context->echo_index);
> >>> +
> >>> +	context->echo_index = MAX_TX_URBS;
> >>> +	atomic_dec(&priv->active_tx_urbs);
> >>> +
> >>> +	netif_wake_queue(priv->netdev);
> >>> +}
> >>> +
> >>> +static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
> >>> +				const struct kvaser_msg *msg)
> >>> +{
> >>> +	struct can_frame *cf;
> >>> +	struct sk_buff *skb;
> >>> +	struct net_device_stats *stats;
> >>> +	struct kvaser_usb_net_priv *priv;
> >>> +	u8 channel, status, txerr, rxerr;
> >>> +
> >>> +	if (msg->id == CMD_CAN_ERROR_EVENT) {
> >>> +		channel = msg->u.error_event.channel;
> >>> +		status =  msg->u.error_event.status;
> >>> +		txerr = msg->u.error_event.tx_errors_count;
> >>> +		rxerr = msg->u.error_event.rx_errors_count;
> >>> +	} else {
> >>> +		channel = msg->u.chip_state_event.channel;
> >>> +		status =  msg->u.chip_state_event.status;
> >>> +		txerr = msg->u.chip_state_event.tx_errors_count;
> >>> +		rxerr = msg->u.chip_state_event.rx_errors_count;
> >>> +	}
> >>> +
> >>> +	if (channel >= dev->nchannels) {
> >>> +		dev_err(dev->udev->dev.parent,
> >>> +			"Invalid channel number (%d)\n", channel);
> >>> +		return;
> >>> +	}
> >>> +
> >>> +	priv = dev->nets[channel];
> >>> +	stats = &priv->netdev->stats;
> >>> +
> >>> +	skb = alloc_can_err_skb(priv->netdev, &cf);
> >>> +	if (!skb) {
> >>> +		stats->rx_dropped++;
> >>> +		return;
> >>> +	}
> >>> +
> >>> +	if ((status & M16C_STATE_BUS_OFF) ||
> >>> +	    (status & M16C_STATE_BUS_RESET)) {
> >>> +		priv->can.state = CAN_STATE_BUS_OFF;
> >>> +		cf->can_id |= CAN_ERR_BUSOFF;
> >>> +		can_bus_off(priv->netdev);
> 
> you should increment priv->can.can_stats.bus_off
> What does the firmware do in this state? Does it automatically try to
> recover and try to send the outstanding frames?

Yes that's what I observed.

> 
> If so, you should turn of the CAN interface, it possible. See:
> http://lxr.free-electrons.com/source/drivers/net/can/at91_can.c#L986

Ok I'll have a look at this.

> 
> Please test Bus-Off behaviour:
> - setup working CAN network
> - short circuit CAN-H and CAN-L wires
> - start "candump any,0:0,#FFFFFFFF" on one shell
> - send one can frame on the other
> 
> then
> 
> - remove the short circuit
> - see if the can frame is transmitted to the other side
> - it should show up as an echo'ed CAN frame on the sender side
> 
> Repeat the same test with disconnecting CAN-H and CAN-L from the other
> CAN station instead of short circuit.
> 
> Please send the output from candump.

1) With the short circuit:

I perform the test you described. It showed that the Kvaser passes from
ERROR-WARNING to ERROR-PASSIVE and then BUS-OFF. But after going to the
state BUS-OFF it comes back to ERROR-WARNING.

  can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
  ...
  can1  200000C8  [8] 00 00 90 00 00 00 00 00   ERRORFRAME  <-- bus off
  can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
  ...
  can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
  can1  123  [2] 11 22	          <-- short circuit removed

I see the echo and on the other end I see the frame coming in.
By the way I see that the txerr and rxerr fields of the structure
kvaser_msg_error_event stay at 0.

2) With CAN-H and CAN-L disconnected:

I never see the bus going in OFF state. It stays in PASSIVE mode.

  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  ...
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
  can1  123  [2] 11 22            <-- other end connected

> 
> >>> +	} else if (status & M16C_STATE_BUS_ERROR) {
> >>> +		priv->can.state = CAN_STATE_ERROR_WARNING;
> >>> +		priv->can.can_stats.error_warning++;
> >>> +	} else if (status & M16C_STATE_BUS_PASSIVE) {
> >>> +		priv->can.state = CAN_STATE_ERROR_PASSIVE;
> >>> +		priv->can.can_stats.error_passive++;
> >>> +	} else {
> >>> +		priv->can.state = CAN_STATE_ERROR_ACTIVE;
> >>> +		cf->can_id |= CAN_ERR_PROT;
> >>> +		cf->data[2] = CAN_ERR_PROT_ACTIVE;
> >>> +	}
> >>> +
> >>> +	if (msg->id == CMD_CAN_ERROR_EVENT) {
> >>> +		u8 error_factor = msg->u.error_event.error_factor;
> >>> +
> >>> +		priv->can.can_stats.bus_error++;
> >>> +		stats->rx_errors++;
> >>> +
> >>> +		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
> >>> +
> >>> +		if ((priv->can.state == CAN_STATE_ERROR_WARNING) ||
> >>> +		    (priv->can.state == CAN_STATE_ERROR_PASSIVE)) {
> >>> +			cf->data[1] = (txerr > rxerr) ?
> >>> +				CAN_ERR_CRTL_TX_PASSIVE
> >>> +				: CAN_ERR_CRTL_RX_PASSIVE;
> >>> +		}
> >>> +
> >>> +		if (error_factor & M16C_EF_ACKE)
> >>> +			cf->data[3] |= (CAN_ERR_PROT_LOC_ACK |
> >>> +					CAN_ERR_PROT_LOC_ACK_DEL);
> >>> +		if (error_factor & M16C_EF_CRCE)
> >>> +			cf->data[3] |= (CAN_ERR_PROT_LOC_CRC_SEQ |
> >>> +					CAN_ERR_PROT_LOC_CRC_DEL);
> >>> +		if (error_factor & M16C_EF_FORME)
> >>> +			cf->data[2] |= CAN_ERR_PROT_FORM;
> >>> +		if (error_factor & M16C_EF_STFE)
> >>> +			cf->data[2] |= CAN_ERR_PROT_STUFF;
> >>> +		if (error_factor & M16C_EF_BITE0)
> >>> +			cf->data[2] |= CAN_ERR_PROT_BIT0;
> >>> +		if (error_factor & M16C_EF_BITE1)
> >>> +			cf->data[2] |= CAN_ERR_PROT_BIT1;
> >>> +		if (error_factor & M16C_EF_TRE)
> >>> +			cf->data[2] |= CAN_ERR_PROT_TX;
> >>> +	}
> >>> +
> >>> +	cf->data[6] = txerr;
> >>> +	cf->data[7] = rxerr;
> >>> +
> >>> +	netif_rx(skb);
> >>> +
> >>> +	priv->bec.txerr = txerr;
> >>> +	priv->bec.rxerr = rxerr;
> >>> +
> >>> +	stats->rx_packets++;
> >>> +	stats->rx_bytes += cf->can_dlc;
> >>> +}
> >>> +
> >>> +static void kvaser_usb_rx_can_msg(const struct kvaser_usb *dev,
> >>> +				  const struct kvaser_msg *msg)
> >>> +{
> >>> +	struct kvaser_usb_net_priv *priv;
> >>> +	struct can_frame *cf;
> >>> +	struct sk_buff *skb;
> >>> +	struct net_device_stats *stats;
> >>> +	u8 channel = msg->u.rx_can.channel;
> >>> +
> >>> +	if (channel >= dev->nchannels) {
> >>> +		dev_err(dev->udev->dev.parent,
> >>> +			"Invalid channel number (%d)\n", channel);
> >>> +		return;
> >>> +	}
> >>> +
> >>> +	priv = dev->nets[channel];
> >>> +	stats = &priv->netdev->stats;
> >>> +
> >>> +	skb = alloc_can_skb(priv->netdev, &cf);
> >>> +	if (skb == NULL) {
> >>> +		stats->tx_dropped++;
> >>> +		return;
> >>> +	}
> >>> +
> >>> +	cf->can_id = ((msg->u.rx_can.msg[0] & 0x1f) << 6) |
> >>> +		     (msg->u.rx_can.msg[1] & 0x3f);
> >>> +	cf->can_dlc = get_can_dlc(msg->u.rx_can.msg[5]);
> >>> +
> >>> +	if (msg->id == CMD_RX_EXT_MESSAGE) {
> >>> +		cf->can_id <<= 18;
> >>> +		cf->can_id += ((msg->u.rx_can.msg[2] & 0x0f) << 14) |
> >>                            |=
> >>
> >> is more appropriate here
> > 
> > Ok.
> > 
> >>
> >>> +			      ((msg->u.rx_can.msg[3] & 0xff) << 6) |
> >>> +			      (msg->u.rx_can.msg[4] & 0x3f);
> >>> +		cf->can_id |= CAN_EFF_FLAG;
> >>> +	}
> >>> +
> >>> +	if (msg->u.rx_can.flag & MSG_FLAG_REMOTE_FRAME) {
> >>> +		cf->can_id |= CAN_RTR_FLAG;
> >>> +	} else if (msg->u.rx_can.flag & (MSG_FLAG_ERROR_FRAME |
> >>> +						MSG_FLAG_NERR)) {
> >>> +		cf->can_id |= CAN_ERR_FLAG;
> >>> +		cf->can_dlc = CAN_ERR_DLC;
> >>
> >> What kind of error is this? Can you set cf->data? What about the
> >> original cd->can_id? What about the stats->rx_*error* stats?
> > 
> > Good question I've to take a look to this.
> > 
> >>
> >>> +	} else if (msg->u.rx_can.flag & MSG_FLAG_OVERRUN) {
> >>> +		cf->can_id = CAN_ERR_FLAG | CAN_ERR_CRTL;
> >>> +		cf->can_dlc = CAN_ERR_DLC;
> >>> +		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
> >>> +
> >>> +		stats->rx_over_errors++;
> >>> +		stats->rx_errors++;
> >>> +	} else if (!msg->u.rx_can.flag) {
> >>> +		memcpy(cf->data, &msg->u.rx_can.msg[6], cf->can_dlc);
> >>> +	} else {
> >>> +		kfree_skb(skb);
> >>> +		return;
> >>> +	}
> >>> +
> >>> +	netif_rx(skb);
> >>> +
> >>> +	stats->rx_packets++;
> >>> +	stats->rx_bytes += cf->can_dlc;
> >>> +}
> >>> +
> >>> +static void kvaser_usb_start_stop_chip_reply(const struct kvaser_usb *dev,
> >>> +					     const struct kvaser_msg *msg)
> >>> +{
> >>> +	struct kvaser_usb_net_priv *priv;
> >>> +	u8 channel = msg->u.simple.channel;
> >>> +
> >>> +	if (channel >= dev->nchannels) {
> >>> +		dev_err(dev->udev->dev.parent,
> >>> +			"Invalid channel number (%d)\n", channel);
> >>> +		return;
> >>> +	}
> >>> +
> >>> +	priv = dev->nets[channel];
> >>> +
> >>> +	complete(&priv->start_stop_comp);
> >>> +}
> >>> +
> >>> +static void kvaser_usb_handle_message(const struct kvaser_usb *dev,
> >>> +				      const struct kvaser_msg *msg)
> >>> +{
> >>> +	switch (msg->id) {
> >>> +	case CMD_START_CHIP_REPLY:
> >>> +	case CMD_STOP_CHIP_REPLY:
> >>> +		kvaser_usb_start_stop_chip_reply(dev, msg);
> >>> +		break;
> >>> +
> >>> +	case CMD_RX_STD_MESSAGE:
> >>> +	case CMD_RX_EXT_MESSAGE:
> >>> +		kvaser_usb_rx_can_msg(dev, msg);
> >>> +		break;
> >>> +
> >>> +	case CMD_CHIP_STATE_EVENT:
> >>> +	case CMD_CAN_ERROR_EVENT:
> >>> +		kvaser_usb_rx_error(dev, msg);
> >>> +		break;
> >>> +
> >>> +	case CMD_TX_ACKNOWLEDGE:
> >>> +		kvaser_usb_tx_acknowledge(dev, msg);
> >>> +		break;
> >>> +
> >>> +	default:
> >>> +		dev_warn(dev->udev->dev.parent,
> >>> +			 "Unhandled message (%d)\n", msg->id);
> >>> +		break;
> >>> +	}
> >>> +}
> >>> +
> >>> +static void kvaser_usb_read_bulk_callback(struct urb *urb)
> >>> +{
> >>> +	struct kvaser_usb *dev = urb->context;
> >>> +	struct kvaser_msg *msg;
> >>> +	int pos = 0;
> >>> +	int err, i;
> >>> +
> >>> +	switch (urb->status) {
> >>> +	case 0:
> >>> +		break;
> >>> +	case -ENOENT:
> >>> +	case -ESHUTDOWN:
> >>> +		return;
> >>> +	default:
> >>> +		dev_info(dev->udev->dev.parent, "Rx URB aborted (%d)\n",
> >>> +			 urb->status);
> >>> +		goto resubmit_urb;
> >>> +	}
> >>> +
> >>> +	while (pos < urb->actual_length) {
> >>
> >> please check here for pos + sizeof(*msg), too
> > 
> > Same as above.
> > 
> >>
> >>> +		msg = urb->transfer_buffer + pos;
> >>> +
> >>> +		if (!msg->len)
> >>> +			break;
> >>> +
> >>> +		kvaser_usb_handle_message(dev, msg);
> >>> +
> >>> +		if (pos > urb->actual_length) {
> >>> +			dev_err(dev->udev->dev.parent, "Format error\n");
> >>> +			break;
> >>> +		}
> >>> +
> >>> +		pos += msg->len;
> >>> +	}
> >>> +
> >>> +resubmit_urb:
> >>> +	usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 129),
> >>                                                                      ^^^
> >>
> >> use #define
> > 
> > Ok.
> > 
> >>
> >>> +			  urb->transfer_buffer, RX_BUFFER_SIZE,
> >>> +			  kvaser_usb_read_bulk_callback, dev);
> >>> +
> >>> +	err = usb_submit_urb(urb, GFP_ATOMIC);
> >>> +	if (err == -ENODEV) {
> >>> +		for (i = 0; i < dev->nchannels; i++) {
> >>> +			if (!dev->nets[i])
> >>> +				continue;
> >>> +
> >>> +			netif_device_detach(dev->nets[i]->netdev);
> >>> +		}
> >>> +	} else if (err) {
> >>> +		dev_err(dev->udev->dev.parent,
> >>> +			"Failed resubmitting read bulk urb: %d\n", err);
> >>> +	}
> >>> +
> >>> +	return;
> >>> +}
> >>> +
> >>> +static int kvaser_usb_setup_rx_urbs(struct kvaser_usb *dev)
> >>> +{
> >>> +	int i, err = 0;
> >>> +
> >>> +	if (dev->rxinitdone)
> >>> +		return 0;
> >>> +
> >>> +	for (i = 0; i < MAX_RX_URBS; i++) {
> >>> +		struct urb *urb = NULL;
> >>> +		u8 *buf = NULL;
> >>> +
> >>> +		urb = usb_alloc_urb(0, GFP_KERNEL);
> >>> +		if (!urb) {
> >>> +			dev_warn(dev->udev->dev.parent,
> >>> +				 "No memory left for URBs\n");
> >>> +			err = -ENOMEM;
> >>> +			break;
> >>> +		}
> >>> +
> >>> +		buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE,
> >>> +					 GFP_KERNEL, &urb->transfer_dma);
> >>> +		if (!buf) {
> >>> +			dev_warn(dev->udev->dev.parent,
> >>> +				 "No memory left for USB buffer\n");
> >>> +			usb_free_urb(urb);
> >>> +			err = -ENOMEM;
> >>> +			break;
> >>> +		}
> >>> +
> >>> +		usb_fill_bulk_urb(urb, dev->udev,
> >>> +				  usb_rcvbulkpipe(dev->udev, 129),
> >>
> >> use #define
> > 
> > Ok.
> > 
> >>
> >>> +				  buf, RX_BUFFER_SIZE,
> >>> +				  kvaser_usb_read_bulk_callback, dev);
> >>> +		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> >>> +		usb_anchor_urb(urb, &dev->rx_submitted);
> >>> +
> >>> +		err = usb_submit_urb(urb, GFP_KERNEL);
> >>> +		if (err) {
> >>> +			usb_unanchor_urb(urb);
> >>> +			usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
> >>> +					  urb->transfer_dma);
> >>> +			break;
> >>> +		}
> >>> +
> >>> +		usb_free_urb(urb);
> >>> +	}
> >>> +
> >>> +	if (i == 0) {
> >>> +		dev_warn(dev->udev->dev.parent,
> >>> +			 "Cannot setup read URBs, error %d\n", err);
> >>> +		return err;
> >>> +	} else if (i < MAX_RX_URBS) {
> >>> +		dev_warn(dev->udev->dev.parent,
> >>> +			 "RX performances may be slow\n");
> >>> +	}
> >>> +
> >>> +	dev->rxinitdone = true;
> >>> +
> >>> +	return 0;
> >>> +}
> >>> +
> >>> +static int kvaser_usb_set_opt_mode(const struct kvaser_usb_net_priv *priv)
> >>> +{
> >>> +	struct kvaser_msg msg;
> >>> +
> >>> +	memset(&msg, 0x00, sizeof(msg));
> >>> +	msg.id = CMD_SET_CTRL_MODE;
> >>> +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_ctrl_mode);
> >>> +	msg.u.ctrl_mode.tid = 0xff;
> >>> +	msg.u.ctrl_mode.channel = priv->channel;
> >>
> >> please use C99 struct initializers
> > 
> > Ok.
> > 
> >>
> >>> +
> >>> +	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
> >>> +		msg.u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_SILENT;
> >>> +	else
> >>> +		msg.u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_NORMAL;
> >>> +
> >>> +	return kvaser_usb_send_msg(priv->dev, &msg);
> >>> +}
> >>> +
> >>> +static int kvaser_usb_start_chip(struct kvaser_usb_net_priv *priv)
> >>> +{
> >>> +	int err;
> >>> +
> >>> +	init_completion(&priv->start_stop_comp);
> >>> +
> >>> +	err = kvaser_usb_send_simple_msg(priv->dev, CMD_START_CHIP,
> >>> +					 priv->channel);
> >>> +	if (err)
> >>> +		return err;
> >>> +
> >>> +	if (!wait_for_completion_timeout(&priv->start_stop_comp,
> >>> +					 msecs_to_jiffies(START_TIMEOUT)))
> >>> +		return -ETIMEDOUT;
> >>> +
> >>> +	return 0;
> >>> +}
> >>> +
> >>> +static int kvaser_usb_open(struct net_device *netdev)
> >>> +{
> >>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> >>> +	struct kvaser_usb *dev = priv->dev;
> >>> +	int err;
> >>> +
> >>> +	err = open_candev(netdev);
> >>> +	if (err)
> >>> +		return err;
> >>> +
> >>> +	err = kvaser_usb_setup_rx_urbs(dev);
> >>> +	if (err)
> >>> +		return err;
> >>> +
> >>> +	err = kvaser_usb_set_opt_mode(priv);
> >>> +	if (err)
> >>> +		return err;
> >>> +
> >>> +	err = kvaser_usb_start_chip(priv);
> >>> +	if (err) {
> >>> +		netdev_warn(netdev, "Cannot start device, error %d\n", err);
> >>> +		close_candev(netdev);
> >>> +		return err;
> >>> +	}
> >>> +
> >>> +	priv->can.state = CAN_STATE_ERROR_ACTIVE;
> >>> +	priv->open_time = jiffies;
> >>> +	netif_start_queue(netdev);
> >>> +
> >>> +	return 0;
> >>> +}
> >>> +
> >>> +static void kvaser_usb_unlink_tx_urbs(struct kvaser_usb_net_priv *priv)
> >>> +{
> >>> +	int i;
> >>> +
> >>> +	usb_kill_anchored_urbs(&priv->tx_submitted);
> >>> +	atomic_set(&priv->active_tx_urbs, 0);
> >>> +
> >>> +	for (i = 0; i < MAX_TX_URBS; i++)
> >> ARRAY_SIZE(priv->tx_contexts) instead of MAX_TX_URBS
> > 
> > Ok.
> > 
> >>> +		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
> >>> +}
> >>> +
> >>> +static void kvaser_usb_unlink_all_urbs(struct kvaser_usb *dev)
> >>> +{
> >>> +	int i;
> >>> +
> >>> +	usb_kill_anchored_urbs(&dev->rx_submitted);
> >>> +
> >>> +	for (i = 0; i < MAX_NET_DEVICES; i++) {
> >> ARRAY_SIZE()
> >>> +		struct kvaser_usb_net_priv *priv = dev->nets[i];
> >>> +
> >>> +		if (priv)
> >>> +			kvaser_usb_unlink_tx_urbs(priv);
> >>> +	}
> >>> +}
> >>> +
> >>> +static int kvaser_usb_stop_chip(struct kvaser_usb_net_priv *priv)
> >>> +{
> >>> +	int err;
> >>> +
> >>> +	init_completion(&priv->start_stop_comp);
> >>> +
> >>> +	err = kvaser_usb_send_simple_msg(priv->dev, CMD_STOP_CHIP,
> >>> +					 priv->channel);
> >>> +	if (err)
> >>> +		return err;
> >>> +
> >>> +	if (!wait_for_completion_timeout(&priv->start_stop_comp,
> >>> +					 msecs_to_jiffies(STOP_TIMEOUT)))
> >>> +		return -ETIMEDOUT;
> >>> +
> >>> +	return 0;
> >>> +}
> >>> +
> >>> +static int kvaser_usb_flush_queue(struct kvaser_usb_net_priv *priv)
> >>> +{
> >>> +	struct kvaser_msg msg;
> >>> +
> >>> +	memset(&msg, 0x00, sizeof(msg));
> >>> +	msg.id = CMD_FLUSH_QUEUE;
> >>> +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_flush_queue);
> >>> +	msg.u.flush_queue.channel = priv->channel;
> >> C99 initialziers, please
> > 
> > Ok.
> > 
> >>> +
> >>> +	return kvaser_usb_send_msg(priv->dev, &msg);
> >>> +}
> >>> +
> >>> +static int kvaser_usb_close(struct net_device *netdev)
> >>> +{
> >>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> >>> +	int err;
> >>> +
> >>> +	netif_stop_queue(netdev);
> >>> +
> >>> +	err = kvaser_usb_flush_queue(priv);
> >>> +	if (err)
> >>> +		netdev_warn(netdev, "Cannot flush queue, error %d\n", err);
> >>> +
> >>> +	err = kvaser_usb_stop_chip(priv);
> >>> +	if (err) {
> >>> +		netdev_warn(netdev, "Cannot stop device, error %d\n", err);
> >>> +		return err;
> >>> +	}
> >>> +
> >>> +	kvaser_usb_unlink_tx_urbs(priv);
> >>> +
> >>> +	priv->can.state = CAN_STATE_STOPPED;
> >>> +	close_candev(priv->netdev);
> >>> +	priv->open_time = 0;
> >>> +
> >>> +	return 0;
> >>> +}
> >>> +
> >>> +static void kvaser_usb_write_bulk_callback(struct urb *urb)
> >>> +{
> >>> +	struct kvaser_usb_tx_urb_context *context = urb->context;
> >>> +	struct kvaser_usb_net_priv *priv;
> >>> +	struct net_device *netdev;
> >>> +
> >>> +	if (WARN_ON(!context))
> >>> +		return;
> >>> +
> >>> +	priv = context->priv;
> >>> +	netdev = priv->netdev;
> >>> +
> >>> +	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
> >>> +			  urb->transfer_buffer, urb->transfer_dma);
> >>> +
> >>> +	if (!netif_device_present(netdev))
> >>> +		return;
> >>> +
> >>> +	if (urb->status)
> >>> +		netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
> >>> +
> >>> +	netdev->trans_start = jiffies;
> >>
> >> Is trans_start needed? at least for non-usb devices it works without.
> > 
> > I don't know, I'll try to figure this out.
> > I see it's used in the two others CAN/USB drivers, 'ems_usb.c' and
> > 'esd_usb2.c'
> > 
> >>
> >>> +}
> >>> +
> >>> +static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
> >>> +					 struct net_device *netdev)
> >>> +{
> >>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> >>> +	struct kvaser_usb *dev = priv->dev;
> >>> +	struct net_device_stats *stats = &netdev->stats;
> >>> +	struct can_frame *cf = (struct can_frame *)skb->data;
> >>> +	struct kvaser_usb_tx_urb_context *context = NULL;
> >>> +	struct urb *urb;
> >>> +	void *buf;
> >>> +	struct kvaser_msg *msg;
> >>> +	int i, err;
> >>> +	int ret = NETDEV_TX_OK;
> >>> +
> >>> +	if (can_dropped_invalid_skb(netdev, skb))
> >>> +		return NETDEV_TX_OK;
> >>> +
> >>> +	urb = usb_alloc_urb(0, GFP_ATOMIC);
> >>> +	if (!urb) {
> >>> +		netdev_err(netdev, "No memory left for URBs\n");
> >>> +		stats->tx_dropped++;
> >>> +		dev_kfree_skb(skb);
> >>> +		goto nourbmem;
> >>> +	}
> >>> +
> >>> +	buf = usb_alloc_coherent(dev->udev, sizeof(struct kvaser_msg),
> >>> +				 GFP_ATOMIC, &urb->transfer_dma);
> >>> +	if (!buf) {
> >>> +		netdev_err(netdev, "No memory left for USB buffer\n");
> >>> +		stats->tx_dropped++;
> >>> +		dev_kfree_skb(skb);
> >>> +		goto nobufmem;
> >>> +	}
> >>> +
> >>> +	msg = (struct kvaser_msg *)buf;
> >>> +	msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_tx_can);
> >>> +	msg->u.tx_can.flags = 0;
> >>> +	msg->u.tx_can.channel = priv->channel;
> >>> +
> >>> +	if (cf->can_id & CAN_EFF_FLAG) {
> >>> +		msg->id = CMD_TX_EXT_MESSAGE;
> >>> +		msg->u.tx_can.msg[0] = (cf->can_id >> 24) & 0x1f;
> >>> +		msg->u.tx_can.msg[1] = (cf->can_id >> 18) & 0x3f;
> >>> +		msg->u.tx_can.msg[2] = (cf->can_id >> 14) & 0x0f;
> >>> +		msg->u.tx_can.msg[3] = (cf->can_id >> 6) & 0xff;
> >>> +		msg->u.tx_can.msg[4] = cf->can_id & 0x3f;
> >>> +	} else {
> >>> +		msg->id = CMD_TX_STD_MESSAGE;
> >>> +		msg->u.tx_can.msg[0] = (cf->can_id >> 6) & 0x1f;
> >>> +		msg->u.tx_can.msg[1] = cf->can_id & 0x3f;
> >>> +	}
> >>> +
> >>> +	msg->u.tx_can.msg[5] = cf->can_dlc;
> >>> +	memcpy(&msg->u.tx_can.msg[6], cf->data, cf->can_dlc);
> >>> +
> >>> +	if (cf->can_id & CAN_RTR_FLAG)
> >>> +		msg->u.tx_can.flags |= MSG_FLAG_REMOTE_FRAME;
> >>> +
> >>> +	for (i = 0; i < MAX_TX_URBS; i++) {
> >> ARRAY_SIZE
> > 
> > Ok.
> > 
> >>> +		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
> >>> +			context = &priv->tx_contexts[i];
> >>> +			break;
> >>> +		}
> >>> +	}
> >>> +
> >>> +	if (!context) {
> >>> +		netdev_warn(netdev, "cannot find free context\n");
> >>> +		ret =  NETDEV_TX_BUSY;
> >>> +		goto releasebuf;
> >>> +	}
> >>> +
> >>> +	context->priv = priv;
> >>> +	context->echo_index = i;
> >>> +	context->dlc = cf->can_dlc;
> >>> +
> >>> +	msg->u.tx_can.tid = context->echo_index;
> >>> +
> >>> +	usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
> >>> +			  buf, msg->len,
> >>> +			  kvaser_usb_write_bulk_callback, context);
> >>> +	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> >>> +	usb_anchor_urb(urb, &priv->tx_submitted);
> >>> +
> >>> +	can_put_echo_skb(skb, netdev, context->echo_index);
> >>> +
> >>> +	atomic_inc(&priv->active_tx_urbs);
> >>> +
> >>> +	if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
> >>> +		netif_stop_queue(netdev);
> >>> +
> >>> +	err = usb_submit_urb(urb, GFP_ATOMIC);
> >>> +	if (unlikely(err)) {
> >>> +		can_free_echo_skb(netdev, context->echo_index);
> >>> +
> >>> +		atomic_dec(&priv->active_tx_urbs);
> >>> +		usb_unanchor_urb(urb);
> >>> +
> >>> +		stats->tx_dropped++;
> >>> +
> >>> +		if (err == -ENODEV)
> >>> +			netif_device_detach(netdev);
> >>> +		else
> >>> +			netdev_warn(netdev, "Failed tx_urb %d\n", err);
> >>> +
> >>> +		goto releasebuf;
> >>> +	}
> >>> +
> >>> +	netdev->trans_start = jiffies;
> >>> +
> >>> +	usb_free_urb(urb);
> >>> +
> >>> +	return NETDEV_TX_OK;
> >>> +
> >>> +releasebuf:
> >>> +	usb_free_coherent(dev->udev, sizeof(struct kvaser_msg),
> >>> +			  buf, urb->transfer_dma);
> >>> +nobufmem:
> >>> +	usb_free_urb(urb);
> >>> +nourbmem:
> >>> +	return ret;
> >>> +}
> >>> +
> >>> +static const struct net_device_ops kvaser_usb_netdev_ops = {
> >>> +	.ndo_open = kvaser_usb_open,
> >>> +	.ndo_stop = kvaser_usb_close,
> >>> +	.ndo_start_xmit = kvaser_usb_start_xmit,
> >>> +};
> >>> +
> >>> +static struct can_bittiming_const kvaser_usb_bittiming_const = {
> >>> +	.name = "kvaser_usb",
> >>> +	.tseg1_min = KVASER_USB_TSEG1_MIN,
> >>> +	.tseg1_max = KVASER_USB_TSEG1_MAX,
> >>> +	.tseg2_min = KVASER_USB_TSEG2_MIN,
> >>> +	.tseg2_max = KVASER_USB_TSEG2_MAX,
> >>> +	.sjw_max = KVASER_USB_SJW_MAX,
> >>> +	.brp_min = KVASER_USB_BRP_MIN,
> >>> +	.brp_max = KVASER_USB_BRP_MAX,
> >>> +	.brp_inc = KVASER_USB_BRP_INC,
> >>> +};
> >>> +
> >>> +static int kvaser_usb_set_bittiming(struct net_device *netdev)
> >>> +{
> >>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> >>> +	struct can_bittiming *bt = &priv->can.bittiming;
> >>> +	struct kvaser_usb *dev = priv->dev;
> >>> +	struct kvaser_msg msg;
> >>> +
> >>> +	msg.id = CMD_SET_BUS_PARAMS;
> >>> +	msg.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_busparams);
> >>> +	msg.u.busparams.channel = priv->channel;
> >>> +	msg.u.busparams.tid = 0xff;
> >>> +	msg.u.busparams.bitrate = bt->bitrate;
> >>
> >> bitrate is le32
> > 
> > Indeed ! I'll fix this.
> > 
> >>
> >>> +	msg.u.busparams.sjw = bt->sjw;
> >>> +	msg.u.busparams.tseg1 = bt->prop_seg + bt->phase_seg1;
> >>> +	msg.u.busparams.tseg2 = bt->phase_seg2;
> >>
> >> C99 initializers, please
> >>
> >>> +
> >>> +	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
> >>> +		msg.u.busparams.no_samp = 3;
> >>> +	else
> >>> +		msg.u.busparams.no_samp = 1;
> >>> +
> >>> +	return kvaser_usb_send_msg(dev, &msg);
> >>> +}
> >>> +
> >>> +static int kvaser_usb_set_mode(struct net_device *netdev,
> >>> +			       enum can_mode mode)
> >>> +{
> >>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> >>> +
> >>> +	if (!priv->open_time)
> >>> +		return -EINVAL;
> >>> +
> >>> +	switch (mode) {
> >>> +	case CAN_MODE_START:
> >>> +		if (netif_queue_stopped(netdev))
> >>> +			netif_wake_queue(netdev);
> >>
> >> No need to restart your USB device?
> > 
> > No. I don't think so.
> > The module continuously tries to transmit the frame and isn't stopped.
> > So there is no need to restart it if it has been explicitely stopped.
> > 
> > When it cannot transmit, the module try again and sends continuously
> > CMD_CAN_ERROR_EVENT frames until it succeeds to transmit the frame.
> > If the device is stopped with the command CMD_STOP_CHIP then it stops
> > sending these CMD_CAN_ERROR_EVENT.
> > Should I handle this in another manner?
> 
> If the firmware automatically recovers from busoff (like the at91 does),
> you should stop the chip it priv->can.restart_ms == 0 and let the chip
> continue working otherwise.
> 
> > 
> >>
> >>> +		break;
> >>> +	default:
> >>> +		return -EOPNOTSUPP;
> >>> +	}
> >>> +
> >>> +	return 0;
> >>> +}
> >>> +
> >>> +static int kvaser_usb_get_berr_counter(const struct net_device *netdev,
> >>> +				       struct can_berr_counter *bec)
> >>> +{
> >>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> >>> +
> >>> +	bec->txerr = priv->bec.txerr;
> >>> +	bec->rxerr = priv->bec.rxerr;
> >>> +
> >>> +	return 0;
> >>> +}
> >>> +
> >>> +static int kvaser_usb_init_one(struct usb_interface *intf,
> >>> +			       const struct usb_device_id *id, int channel)
> >>> +{
> >>> +	struct kvaser_usb *dev = usb_get_intfdata(intf);
> >>> +	struct net_device *netdev;
> >>> +	struct kvaser_usb_net_priv *priv;
> >>> +	int i, err;
> >>> +
> >>> +	netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
> >>> +	if (!netdev) {
> >>> +		dev_err(&intf->dev, "Cannot alloc candev\n");
> >>> +		return -ENOMEM;
> >>> +	}
> >>> +
> >>> +	priv = netdev_priv(netdev);
> >>> +
> >>> +	init_usb_anchor(&priv->tx_submitted);
> >>> +	atomic_set(&priv->active_tx_urbs, 0);
> >>> +
> >>> +	for (i = 0; i < MAX_TX_URBS; i++)
> >>> +		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
> >>> +
> >>> +	priv->dev = dev;
> >>> +	priv->netdev = netdev;
> >>> +	priv->channel = channel;
> >>> +
> >>> +	priv->can.state = CAN_STATE_STOPPED;
> >>> +	priv->can.clock.freq = CAN_USB_CLOCK;
> >>> +	priv->can.bittiming_const = &kvaser_usb_bittiming_const;
> >>> +	priv->can.do_set_bittiming = kvaser_usb_set_bittiming;
> >>> +	priv->can.do_set_mode = kvaser_usb_set_mode;
> >>> +	priv->can.do_get_berr_counter = kvaser_usb_get_berr_counter;
> >>> +	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
> >>> +	if (id->driver_info & KVASER_HAS_SILENT_MODE)
> >>> +		priv->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
> >>> +
> >>> +	netdev->flags |= IFF_ECHO;
> >>> +
> >>> +	netdev->netdev_ops = &kvaser_usb_netdev_ops;
> >>> +
> >>> +	SET_NETDEV_DEV(netdev, &intf->dev);
> >>> +
> >>> +	err = register_candev(netdev);
> >>> +	if (err) {
> >>> +		dev_err(&intf->dev, "Failed to register can device\n");
> >>> +		free_candev(netdev);
> >>> +		return err;
> >>> +	}
> >>> +
> >>> +	dev->nets[channel] = priv;
> >>> +	netdev_info(netdev, "device %s registered\n", netdev->name);
> >>
> >> netdev_info should take care of printing the device's name.
> > 
> > Ok.
> > 
> >>> +
> >>> +	return 0;
> >>> +}
> >>> +
> >>> +static int kvaser_usb_probe(struct usb_interface *intf,
> >>> +			    const struct usb_device_id *id)
> >>> +{
> >>> +	struct kvaser_usb *dev;
> >>> +	int err = -ENOMEM;
> >>> +	int i;
> >>> +
> >>> +	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
> >>
> >> Who will free dev on driver unload? Please make use of devm_kzalloc().
> > 
> > Ok. kfree is missing is disconnect().
> > I'll replace it by devm_kzalloc() and devm_free().
> 
> The beauty of devm_kzalloc is you don't have to call *_free, its
> automatically called if probe fails or when remove function has been called.

Cool :-)

> 
> > 
> >>
> >>> +	if (!dev)
> >>> +		return -ENOMEM;
> >>> +
> >>> +	dev->udev = interface_to_usbdev(intf);
> >>> +
> >>> +	init_usb_anchor(&dev->rx_submitted);
> >>> +
> >>> +	usb_set_intfdata(intf, dev);
> >>> +
> >>> +	if (kvaser_usb_send_simple_msg(dev, CMD_RESET_CHIP, 0)) {
> >>> +		dev_err(&intf->dev, "Cannot reset kvaser\n");
> >>> +		goto error;
> >>> +	}
> >>> +
> >>> +	if (kvaser_usb_get_software_info(dev)) {
> >>> +		dev_err(&intf->dev, "Cannot get software infos\n");
> >>> +		goto error;
> >>> +	}
> >>> +
> >>> +	if (kvaser_usb_get_card_info(dev)) {
> >>> +		dev_err(&intf->dev, "Cannot get card infos\n");
> >>> +		goto error;
> >>> +	}
> >>> +
> >>> +	dev_dbg(&intf->dev, "Firmware version: %d.%d.%d\n",
> >>> +		 ((dev->fw_version >> 24) & 0xff),
> >>> +		 ((dev->fw_version >> 16) & 0xff),
> >>> +		 (dev->fw_version & 0xffff));
> >>> +
> >>> +	for (i = 0; i < dev->nchannels; i++)
> >>> +		kvaser_usb_init_one(intf, id, i);
> >>> +
> >>> +	return 0;
> >>> +
> >>> +error:
> >>> +	kfree(dev);
> >>> +	return err;
> >>> +}
> >>> +
> >>> +static void kvaser_usb_disconnect(struct usb_interface *intf)
> >>> +{
> >>> +	struct kvaser_usb *dev = usb_get_intfdata(intf);
> >>> +	int i;
> >>> +
> >>> +	usb_set_intfdata(intf, NULL);
> >>> +
> >>> +	if (!dev)
> >>> +		return;
> >>> +
> >>> +	for (i = 0; i < dev->nchannels; i++) {
> >>> +		if (!dev->nets[i])
> >>> +			continue;
> >>> +
> >>> +		unregister_netdev(dev->nets[i]->netdev);
> >>> +		free_candev(dev->nets[i]->netdev);
> >>> +	}
> >>> +
> >>> +	kvaser_usb_unlink_all_urbs(dev);
> >>> +}
> >>> +
> >>> +static struct usb_driver kvaser_usb_driver = {
> >>> +	.name = "kvaser_usb",
> >>> +	.probe = kvaser_usb_probe,
> >>> +	.disconnect = kvaser_usb_disconnect,
> >>> +	.id_table = kvaser_usb_table
> >>> +};
> >>> +
> >>> +module_usb_driver(kvaser_usb_driver);
> >>> +
> >>> +MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
> >>> +MODULE_DESCRIPTION("Can driver for Kvaser CAN/USB devices");
> >>> +MODULE_LICENSE("GPL v2");
> >>> diff --git a/drivers/net/can/usb/kvaser_usb.h b/drivers/net/can/usb/kvaser_usb.h
> >>> new file mode 100644
> >>> index 0000000..8e0b6ab
> >>> --- /dev/null
> >>> +++ b/drivers/net/can/usb/kvaser_usb.h
> >>> @@ -0,0 +1,237 @@
> >>> +#ifndef _KVASER_USB_H_
> >>> +#define _KVASER_USB_H_
> >>> +
> >>> +#define	MAX_TX_URBS			16
> >> Please no tab between define and macro name
> > 
> > Ok I didn't know it was not allowed... checkpatch didn't complain.
> 
> It's allowed, but not used without tab it's more common, at least among
> CAN drivers.
> 
> > 
> >>> +#define	MAX_RX_URBS			4
> >>> +#define	START_TIMEOUT			1000
> >>> +#define	STOP_TIMEOUT			1000
> >>> +#define	USB_SEND_TIMEOUT		1000
> >>> +#define	USB_RECEIVE_TIMEOUT		1000
> >>> +#define	RX_BUFFER_SIZE			3072
> >>> +#define	CAN_USB_CLOCK			8000000
> >>> +#define	MAX_NET_DEVICES			3
> >>> +
> >>> +/* Kvaser USB devices */
> >>> +#define	KVASER_VENDOR_ID		0x0bfd
> >>> +#define	USB_LEAF_DEVEL_PRODUCT_ID	10
> >>> +#define	USB_LEAF_LITE_PRODUCT_ID	11
> >>> +#define	USB_LEAF_PRO_PRODUCT_ID		12
> >>> +#define	USB_LEAF_SPRO_PRODUCT_ID	14
> >>> +#define	USB_LEAF_PRO_LS_PRODUCT_ID	15
> >>> +#define	USB_LEAF_PRO_SWC_PRODUCT_ID	16
> >>> +#define	USB_LEAF_PRO_LIN_PRODUCT_ID	17
> >>> +#define	USB_LEAF_SPRO_LS_PRODUCT_ID	18
> >>> +#define	USB_LEAF_SPRO_SWC_PRODUCT_ID	19
> >>> +#define	USB_MEMO2_DEVEL_PRODUCT_ID	22
> >>> +#define	USB_MEMO2_HSHS_PRODUCT_ID	23
> >>> +#define	USB_UPRO_HSHS_PRODUCT_ID	24
> >>> +#define	USB_LEAF_LITE_GI_PRODUCT_ID	25
> >>> +#define	USB_LEAF_PRO_OBDII_PRODUCT_ID	26
> >>> +#define	USB_MEMO2_HSLS_PRODUCT_ID	27
> >>> +#define	USB_LEAF_LITE_CH_PRODUCT_ID	28
> >>> +#define	USB_BLACKBIRD_SPRO_PRODUCT_ID	29
> >>> +#define	USB_OEM_MERCURY_PRODUCT_ID	34
> >>> +#define	USB_OEM_LEAF_PRODUCT_ID		35
> >>> +#define	USB_CAN_R_PRODUCT_ID		39
> >>> +
> >>> +/* USB devices features */
> >>> +#define	KVASER_HAS_SILENT_MODE		(1 << 0)
> >> pleae use BIT(0)
> >>> +
> >>> +/* Message header size */
> >>> +#define	MSG_HEADER_LEN			2
> >>> +
> >>> +/* Can message flags */
> >>> +#define	MSG_FLAG_ERROR_FRAME		(1 << 0)
> >>> +#define	MSG_FLAG_OVERRUN		(1 << 1)
> >>> +#define	MSG_FLAG_NERR			(1 << 2)
> >>> +#define	MSG_FLAG_WAKEUP			(1 << 3)
> >>> +#define	MSG_FLAG_REMOTE_FRAME		(1 << 4)
> >>> +#define	MSG_FLAG_RESERVED		(1 << 5)
> >>> +#define	MSG_FLAG_TX_ACK			(1 << 6)
> >>> +#define	MSG_FLAG_TX_REQUEST		(1 << 7)
> >>> +
> >>> +/* Can states */
> >>> +#define	M16C_STATE_BUS_RESET		(1 << 0)
> >>> +#define	M16C_STATE_BUS_ERROR		(1 << 4)
> >>> +#define	M16C_STATE_BUS_PASSIVE		(1 << 5)
> >>> +#define	M16C_STATE_BUS_OFF		(1 << 6)
> >>> +
> >>> +/* Can msg ids */
> >>> +#define	CMD_RX_STD_MESSAGE		12
> >>> +#define	CMD_TX_STD_MESSAGE		13
> >>> +#define	CMD_RX_EXT_MESSAGE		14
> >>> +#define	CMD_TX_EXT_MESSAGE		15
> >>> +#define	CMD_SET_BUS_PARAMS		16
> >>> +#define	CMD_GET_BUS_PARAMS		17
> >>> +#define	CMD_GET_BUS_PARAMS_REPLY	18
> >>> +#define	CMD_GET_CHIP_STATE		19
> >>> +#define	CMD_CHIP_STATE_EVENT		20
> >>> +#define	CMD_SET_CTRL_MODE		21
> >>> +#define	CMD_GET_CTRL_MODE		22
> >>> +#define	CMD_GET_CTRL_MODE_REPLY		23
> >>> +#define	CMD_RESET_CHIP			24
> >>> +#define	CMD_RESET_CHIP_REPLY		25
> >>> +#define	CMD_START_CHIP			26
> >>> +#define	CMD_START_CHIP_REPLY		27
> >>> +#define	CMD_STOP_CHIP			28
> >>> +#define	CMD_STOP_CHIP_REPLY		29
> >>> +#define	CMD_GET_CARD_INFO2		32
> >>> +#define	CMD_GET_CARD_INFO		34
> >>> +#define	CMD_GET_CARD_INFO_REPLY		35
> >>> +#define	CMD_GET_SOFTWARE_INFO		38
> >>> +#define	CMD_GET_SOFTWARE_INFO_REPLY	39
> >>> +#define	CMD_ERROR_EVENT			45
> >>> +#define	CMD_FLUSH_QUEUE			48
> >>> +#define	CMD_TX_ACKNOWLEDGE		50
> >>> +#define	CMD_CAN_ERROR_EVENT		51
> >>> +#define	CMD_USB_THROTTLE		77
> >>> +
> >>> +/* error factors */
> >>> +#define	M16C_EF_ACKE			(1 << 0)
> >>> +#define	M16C_EF_CRCE			(1 << 1)
> >>> +#define	M16C_EF_FORME			(1 << 2)
> >>> +#define	M16C_EF_STFE			(1 << 3)
> >>> +#define	M16C_EF_BITE0			(1 << 4)
> >>> +#define	M16C_EF_BITE1			(1 << 5)
> >>> +#define	M16C_EF_RCVE			(1 << 6)
> >>> +#define	M16C_EF_TRE			(1 << 7)
> >>> +
> >>> +/* bittiming parameters */
> >>> +#define	KVASER_USB_TSEG1_MIN		1
> >>> +#define	KVASER_USB_TSEG1_MAX		16
> >>> +#define	KVASER_USB_TSEG2_MIN		1
> >>> +#define	KVASER_USB_TSEG2_MAX		8
> >>> +#define	KVASER_USB_SJW_MAX		4
> >>> +#define	KVASER_USB_BRP_MIN		1
> >>> +#define	KVASER_USB_BRP_MAX		64
> >>> +#define	KVASER_USB_BRP_INC		1
> >>> +
> >>> +/* ctrl modes */
> >>> +#define	KVASER_CTRL_MODE_NORMAL		1
> >>> +#define	KVASER_CTRL_MODE_SILENT		2
> >>> +#define	KVASER_CTRL_MODE_SELFRECEPTION	3
> >>> +#define	KVASER_CTRL_MODE_OFF		4
> >>> +
> >>> +struct kvaser_msg_simple {
> >>> +	u8 tid;
> >>> +	u8 channel;
> >>> +} __packed;
> >>> +
> >>> +struct kvaser_msg_cardinfo {
> >>> +	u8 tid;
> >>> +	u8 nchannels;
> >>> +	__le32 serial_number;
> >>> +	__le32 padding;
> >>> +	__le32 clock_resolution;
> >>> +	__le32 mfgdate;
> >>> +	u8 ean[8];
> >>> +	u8 hw_revision;
> >>> +	u8 usb_hs_mode;
> >>> +	__le16 padding2;
> >>> +} __packed;
> >>> +
> >>> +struct kvaser_msg_cardinfo2 {
> >>> +	u8 tid;
> >>> +	u8 channel;
> >>> +	u8 pcb_id[24];
> >>> +	__le32 oem_unlock_code;
> >>> +} __packed;
> >>> +
> >>> +struct kvaser_msg_softinfo {
> >>> +	u8 tid;
> >>> +	u8 channel;
> >>> +	__le32 sw_options;
> >>> +	__le32 fw_version;
> >>> +	__le16 max_outstanding_tx;
> >>> +	__le16 padding[9];
> >>> +} __packed;
> >>> +
> >>> +struct kvaser_msg_busparams {
> >>> +	u8 tid;
> >>> +	u8 channel;
> >>> +	__le32 bitrate;
> >>> +	u8 tseg1;
> >>> +	u8 tseg2;
> >>> +	u8 sjw;
> >>> +	u8 no_samp;
> >>> +} __packed;
> >>> +
> >>> +struct kvaser_msg_tx_can {
> >>> +	u8 channel;
> >>> +	u8 tid;
> >>> +	u8 msg[14];
> >>> +	u8 padding;
> >>> +	u8 flags;
> >>> +} __packed;
> >>> +
> >>> +struct kvaser_msg_rx_can {
> >>> +	u8 channel;
> >>> +	u8 flag;
> >>> +	__le16 time[3];
> >>> +	u8 msg[14];
> >>> +} __packed;
> >>> +
> >>> +struct kvaser_msg_chip_state_event {
> >>> +	u8 tid;
> >>> +	u8 channel;
> >>> +	__le16 time[3];
> >>> +	u8 tx_errors_count;
> >>> +	u8 rx_errors_count;
> >>> +	u8 status;
> >>> +	u8 padding[3];
> >>> +} __packed;
> >>> +
> >>> +struct kvaser_msg_tx_acknowledge {
> >>> +	u8 channel;
> >>> +	u8 tid;
> >>> +	__le16 time[3];
> >>> +	u8 flags;
> >>> +	u8 time_offset;
> >>> +} __packed;
> >>> +
> >>> +struct kvaser_msg_error_event {
> >>> +	u8 tid;
> >>> +	u8 flags;
> >>> +	__le16 time[3];
> >>> +	u8 channel;
> >>> +	u8 padding;
> >>> +	u8 tx_errors_count;
> >>> +	u8 rx_errors_count;
> >>> +	u8 status;
> >>> +	u8 error_factor;
> >>> +} __packed;
> >>> +
> >>> +struct kvaser_msg_ctrl_mode {
> >>> +	u8 tid;
> >>> +	u8 channel;
> >>> +	u8 ctrl_mode;
> >>> +	u8 padding[3];
> >>> +} __packed;
> >>> +
> >>> +struct kvaser_msg_flush_queue {
> >>> +	u8 tid;
> >>> +	u8 channel;
> >>> +	u8 flags;
> >>> +	u8 padding[3];
> >>> +} __packed;
> >>> +
> >>> +struct kvaser_msg {
> >>> +	u8 len;
> >>> +	u8 id;
> >>> +	union	{
> >>> +		struct kvaser_msg_simple simple;
> >>> +		struct kvaser_msg_cardinfo cardinfo;
> >>> +		struct kvaser_msg_cardinfo2 cardinfo2;
> >>> +		struct kvaser_msg_softinfo softinfo;
> >>> +		struct kvaser_msg_busparams busparams;
> >>> +		struct kvaser_msg_tx_can tx_can;
> >>> +		struct kvaser_msg_rx_can rx_can;
> >>> +		struct kvaser_msg_chip_state_event chip_state_event;
> >>> +		struct kvaser_msg_tx_acknowledge tx_acknowledge;
> >>> +		struct kvaser_msg_error_event error_event;
> >>> +		struct kvaser_msg_ctrl_mode ctrl_mode;
> >>> +		struct kvaser_msg_ctrl_mode flush_queue;
> >>> +	} u;
> >>> +} __packed;
> >>> +
> >>> +#endif
> >>>
> >>
> >>
> >> -- 
> >> Pengutronix e.K.                  | Marc Kleine-Budde           |
> >> Industrial Linux Solutions        | Phone: +49-231-2826-924     |
> >> Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
> >> Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |
> >>
> > 
> > Thanks for the review.
> np,
> 
> regards, Marc
> 
> -- 
> Pengutronix e.K.                  | Marc Kleine-Budde           |
> Industrial Linux Solutions        | Phone: +49-231-2826-924     |
> Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
> Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |
> 

Thanks,

On 07/31/2012 03:06 PM, Olivier Sobrie wrote:
[...]

>>>> Please check if your driver survives hot-unplugging while sending and
>>>> receiving CAN frames at maximum laod.
>>>
>>> I tested this with two Kvaser sending frames with "cangen can0 -g 0 -i"
>>> never saw a crash.
>>
>> Please test send sending and receiving at the same time.
> 
> Yes that's what I did; "cangen can0 -g 0 -i" on both sides.

Fine.

[...]

>>>>> --- /dev/null
>>>>> +++ b/drivers/net/can/usb/kvaser_usb.c
>>>>> @@ -0,0 +1,1062 @@
>>>>> +/*
>>>>
>>>> Please add a license statement and probably your copyright:
>>>>
>>>>  * This program is free software; you can redistribute it and/or
>>>>  * modify it under the terms of the GNU General Public License as
>>>>  * published by the Free Software Foundation version 2.
>>>>
>>>> You also should copy the copyright from the drivers you used:
>>>>
>>>>> + * Parts of this driver are based on the following:
>>>>> + *  - Kvaser linux leaf driver (version 4.78)
>>>>
>>>> I just downloaded their driver and noticed that it's quite sparse on
>>>> stating the license the code is released under.
>>>> "doc/HTMLhelp/copyright.htx" is quite restrictive, the word GPL occurs 3
>>>> times, all in MODULE_LICENSE("GPL"). Running modinfo on the usbcan.ko
>>>> shows "license: GPL"
>>>
>>> I'll add the license statement.
>>> In fact it's the leaf.ko which is used for this device and it is under
>>> GPL as modinfo said.
>>
>> I just talked to my boss and we're the same opinion, that
>> MODULE_LICENSE("GPL") is a technical term and not relevant if the
>> included license doesn't say a word about GPL. If the kvaser tarball
>> violates the GPL, however is written on different sheet of paper (as we
>> say in Germany).
>>
>> So I cannot put my S-o-b under this driver as long as we haven't talked
>> to kvaser.
> 
> Ok I thought it was sufficient enough to have MODULE_LICENSE("GPL") in
> the code to indicate it is a GPL driver. I'll ask Kvaser before sending
> any new version of the patch.

We can continue the review process, this problem has to be sorted out
before I can apply this patch to linux-can-next tree.

[...]

>>>>> +static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
>>>>> +				const struct kvaser_msg *msg)
>>>>> +{
>>>>> +	struct can_frame *cf;
>>>>> +	struct sk_buff *skb;
>>>>> +	struct net_device_stats *stats;
>>>>> +	struct kvaser_usb_net_priv *priv;
>>>>> +	u8 channel, status, txerr, rxerr;
>>>>> +
>>>>> +	if (msg->id == CMD_CAN_ERROR_EVENT) {
>>>>> +		channel = msg->u.error_event.channel;
>>>>> +		status =  msg->u.error_event.status;
>>>>> +		txerr = msg->u.error_event.tx_errors_count;
>>>>> +		rxerr = msg->u.error_event.rx_errors_count;
>>>>> +	} else {
>>>>> +		channel = msg->u.chip_state_event.channel;
>>>>> +		status =  msg->u.chip_state_event.status;
>>>>> +		txerr = msg->u.chip_state_event.tx_errors_count;
>>>>> +		rxerr = msg->u.chip_state_event.rx_errors_count;
>>>>> +	}
>>>>> +
>>>>> +	if (channel >= dev->nchannels) {
>>>>> +		dev_err(dev->udev->dev.parent,
>>>>> +			"Invalid channel number (%d)\n", channel);
>>>>> +		return;
>>>>> +	}
>>>>> +
>>>>> +	priv = dev->nets[channel];
>>>>> +	stats = &priv->netdev->stats;
>>>>> +
>>>>> +	skb = alloc_can_err_skb(priv->netdev, &cf);
>>>>> +	if (!skb) {
>>>>> +		stats->rx_dropped++;
>>>>> +		return;
>>>>> +	}
>>>>> +
>>>>> +	if ((status & M16C_STATE_BUS_OFF) ||
>>>>> +	    (status & M16C_STATE_BUS_RESET)) {
>>>>> +		priv->can.state = CAN_STATE_BUS_OFF;
>>>>> +		cf->can_id |= CAN_ERR_BUSOFF;
>>>>> +		can_bus_off(priv->netdev);
>>
>> you should increment priv->can.can_stats.bus_off
>> What does the firmware do in this state? Does it automatically try to
>> recover and try to send the outstanding frames?
> 
> Yes that's what I observed.

It's behaves like the at91_can.

>> If so, you should turn of the CAN interface, it possible. See:
>> http://lxr.free-electrons.com/source/drivers/net/can/at91_can.c#L986
> 
> Ok I'll have a look at this.
> 
>>
>> Please test Bus-Off behaviour:
>> - setup working CAN network
>> - short circuit CAN-H and CAN-L wires
>> - start "candump any,0:0,#FFFFFFFF" on one shell
>> - send one can frame on the other
>>
>> then
>>
>> - remove the short circuit
>> - see if the can frame is transmitted to the other side
>> - it should show up as an echo'ed CAN frame on the sender side
>>
>> Repeat the same test with disconnecting CAN-H and CAN-L from the other
>> CAN station instead of short circuit.
>>
>> Please send the output from candump.
> 
> 1) With the short circuit:
> 
> I perform the test you described. It showed that the Kvaser passes from
> ERROR-WARNING to ERROR-PASSIVE and then BUS-OFF. But after going to the
> state BUS-OFF it comes back to ERROR-WARNING.
> 
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME

Why don't we have any rx/tx numbers in the error frame?

>   ...
>   can1  200000C8  [8] 00 00 90 00 00 00 00 00   ERRORFRAME  <-- bus off
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   ...
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  123  [2] 11 22	          <-- short circuit removed
> 
> I see the echo and on the other end I see the frame coming in.
> By the way I see that the txerr and rxerr fields of the structure
> kvaser_msg_error_event stay at 0.
> 
> 2) With CAN-H and CAN-L disconnected:
> 
> I never see the bus going in OFF state. It stays in PASSIVE mode.
> 
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   ...
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 80 1B 00 00 00 00   ERRORFRAME
>   can1  123  [2] 11 22            <-- other end connected

From the hardware point of view the short circuit and open end tests
look good. Please adjust the driver to turn off the CAN interface in
case of a bus off if restart_ms is 0.

>>>>> +	} else if (status & M16C_STATE_BUS_ERROR) {
>>>>> +		priv->can.state = CAN_STATE_ERROR_WARNING;
>>>>> +		priv->can.can_stats.error_warning++;
>>>>> +	} else if (status & M16C_STATE_BUS_PASSIVE) {
>>>>> +		priv->can.state = CAN_STATE_ERROR_PASSIVE;
>>>>> +		priv->can.can_stats.error_passive++;
>>>>> +	} else {
>>>>> +		priv->can.state = CAN_STATE_ERROR_ACTIVE;
>>>>> +		cf->can_id |= CAN_ERR_PROT;
>>>>> +		cf->data[2] = CAN_ERR_PROT_ACTIVE;
>>>>> +	}
>>>>> +
>>>>> +	if (msg->id == CMD_CAN_ERROR_EVENT) {
>>>>> +		u8 error_factor = msg->u.error_event.error_factor;
>>>>> +
>>>>> +		priv->can.can_stats.bus_error++;
>>>>> +		stats->rx_errors++;
>>>>> +
>>>>> +		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
>>>>> +
>>>>> +		if ((priv->can.state == CAN_STATE_ERROR_WARNING) ||
>>>>> +		    (priv->can.state == CAN_STATE_ERROR_PASSIVE)) {
>>>>> +			cf->data[1] = (txerr > rxerr) ?
>>>>> +				CAN_ERR_CRTL_TX_PASSIVE
>>>>> +				: CAN_ERR_CRTL_RX_PASSIVE;

Please use CAN_ERR_CRTL_RX_WARNING, CAN_ERR_CRTL_TX_WARNING where
appropriate.

>>>>> +		}
>>>>> +
>>>>> +		if (error_factor & M16C_EF_ACKE)
>>>>> +			cf->data[3] |= (CAN_ERR_PROT_LOC_ACK |
>>>>> +					CAN_ERR_PROT_LOC_ACK_DEL);
>>>>> +		if (error_factor & M16C_EF_CRCE)
>>>>> +			cf->data[3] |= (CAN_ERR_PROT_LOC_CRC_SEQ |
>>>>> +					CAN_ERR_PROT_LOC_CRC_DEL);
>>>>> +		if (error_factor & M16C_EF_FORME)
>>>>> +			cf->data[2] |= CAN_ERR_PROT_FORM;
>>>>> +		if (error_factor & M16C_EF_STFE)
>>>>> +			cf->data[2] |= CAN_ERR_PROT_STUFF;
>>>>> +		if (error_factor & M16C_EF_BITE0)
>>>>> +			cf->data[2] |= CAN_ERR_PROT_BIT0;
>>>>> +		if (error_factor & M16C_EF_BITE1)
>>>>> +			cf->data[2] |= CAN_ERR_PROT_BIT1;
>>>>> +		if (error_factor & M16C_EF_TRE)
>>>>> +			cf->data[2] |= CAN_ERR_PROT_TX;
>>>>> +	}
>>>>> +
>>>>> +	cf->data[6] = txerr;
>>>>> +	cf->data[7] = rxerr;
>>>>> +
>>>>> +	netif_rx(skb);
>>>>> +
>>>>> +	priv->bec.txerr = txerr;
>>>>> +	priv->bec.rxerr = rxerr;
>>>>> +
>>>>> +	stats->rx_packets++;
>>>>> +	stats->rx_bytes += cf->can_dlc;
>>>>> +}
>>>>> +

[...]

>>>>> +static int kvaser_usb_get_berr_counter(const struct net_device *netdev,
>>>>> +				       struct can_berr_counter *bec)
>>>>> +{
>>>>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
>>>>> +
>>>>> +	bec->txerr = priv->bec.txerr;
>>>>> +	bec->rxerr = priv->bec.rxerr;

I think you can copy the struct like this:

	*bec = priv->bec;

>>>>> +
>>>>> +	return 0;
>>>>> +}

Marc

On 07/31/2012 03:06 PM, Olivier Sobrie wrote:
> On Tue, Jul 31, 2012 at 11:56:22AM +0200, Marc Kleine-Budde wrote:
...
>> Please test Bus-Off behaviour:
>> - setup working CAN network
>> - short circuit CAN-H and CAN-L wires
>> - start "candump any,0:0,#FFFFFFFF" on one shell
>> - send one can frame on the other
>>
>> then
>>
>> - remove the short circuit
>> - see if the can frame is transmitted to the other side
>> - it should show up as an echo'ed CAN frame on the sender side
>>
>> Repeat the same test with disconnecting CAN-H and CAN-L from the other
>> CAN station instead of short circuit.
>>
>> Please send the output from candump.
> 
> 1) With the short circuit:
> 
> I perform the test you described. It showed that the Kvaser passes from
> ERROR-WARNING to ERROR-PASSIVE and then BUS-OFF. But after going to the
> state BUS-OFF it comes back to ERROR-WARNING.

You can use the option "-e" to get a human readable output.

>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME

A state change (0x10 here) should only be reported once.

>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   ...
>   can1  200000C8  [8] 00 00 90 00 00 00 00 00   ERRORFRAME  <-- bus off
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   ...
>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>   can1  123  [2] 11 22	          <-- short circuit removed
> 
> I see the echo and on the other end I see the frame coming in.
> By the way I see that the txerr and rxerr fields of the structure
> kvaser_msg_error_event stay at 0.

If possible, they should be set for any CAN error message.

> 
> 2) With CAN-H and CAN-L disconnected:
> 
> I never see the bus going in OFF state. It stays in PASSIVE mode.

That is the correct behavior. You should get ACK slot (and not ACK
delimiter), IIRC.

I'm offline for the rest of the week. I will have a closer look next
week (to your next version(s)).

Wolfgang.

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Hello,

On Tue, Jul 31, 2012 at 03:27:55PM +0200, Marc Kleine-Budde wrote:
> We can continue the review process, this problem has to be sorted out
> before I can apply this patch to linux-can-next tree.

Ok.

> > 1) With the short circuit:
> > 
> > I perform the test you described. It showed that the Kvaser passes from
> > ERROR-WARNING to ERROR-PASSIVE and then BUS-OFF. But after going to the
> > state BUS-OFF it comes back to ERROR-WARNING.
> > 
> >   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
> >   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
> >   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
> >   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
> >   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
> >   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
> >   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
> >   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
> >   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
> 
> Why don't we have any rx/tx numbers in the error frame?

Because the hardware seems to not update the tx/rx_errors_count
fields :-(

> From the hardware point of view the short circuit and open end tests
> look good. Please adjust the driver to turn off the CAN interface in
> case of a bus off if restart_ms is 0.

And in the case where restart_ms is not 0? Don't I've to put it off so
and drop the frame?
I actually implemeted it as you said and here is what I observed in
candump output with restart_ms set to 100 ms:

t0: Short circuit between CAN-H and CAN-L + cansend can1 123#1122
  can1  2000008C  [8] 00 04 90 00 00 00 00 00   ERRORFRAME
	controller-problem{rx-error-warning}
	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
	bus-error
  can1  2000008C  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
	controller-problem{rx-error-passive}
	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
	bus-error
  can1  200000C8  [8] 00 00 90 00 00 00 00 00   ERRORFRAME
	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
	bus-off
	bus-error
...
  can1  2000008C  [8] 00 04 90 00 00 00 00 00   ERRORFRAME
	controller-problem{rx-error-warning}
	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
	bus-error
  can1  2000008C  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
	controller-problem{rx-error-passive}
	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
	bus-error
  can1  200000C8  [8] 00 00 90 00 00 00 00 00   ERRORFRAME
	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
	bus-off
	bus-error

t1: short circuit removed
  can1  123  [2] 11 22
  can1  20000100  [8] 00 00 00 00 00 00 00 00   ERRORFRAME
	restarted-after-bus-of

The echo coming before the restart looks weird? No?
Shouldn't we drop the frame once BUF-OFF is reached?

> >>>>> +		if ((priv->can.state == CAN_STATE_ERROR_WARNING) ||
> >>>>> +		    (priv->can.state == CAN_STATE_ERROR_PASSIVE)) {
> >>>>> +			cf->data[1] = (txerr > rxerr) ?
> >>>>> +				CAN_ERR_CRTL_TX_PASSIVE
> >>>>> +				: CAN_ERR_CRTL_RX_PASSIVE;
> 
> Please use CAN_ERR_CRTL_RX_WARNING, CAN_ERR_CRTL_TX_WARNING where
> appropriate.

Ok. As the hardware doesn't report good values for txerr and rxerr, I'll
also remove the tests on txerr and rxerr.
I observed the same behavior with the original driver.
I asked Kvaser for this problem. I've to wait before their developer is
back (same for the GPL issue).

> >>>>> +static int kvaser_usb_get_berr_counter(const struct net_device *netdev,
> >>>>> +				       struct can_berr_counter *bec)
> >>>>> +{
> >>>>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> >>>>> +
> >>>>> +	bec->txerr = priv->bec.txerr;
> >>>>> +	bec->rxerr = priv->bec.rxerr;
> 
> I think you can copy the struct like this:
> 
> 	*bec = priv->bec;

Thanks. I'll remove the function kvaser_usb_get_berr_counter as the
hardware seems to never report txerr and rxerr.

I'll look deeper at this driver during the week-end if possible...

Thanks a lot for your help,

On 08/02/2012 12:53 PM, Olivier Sobrie wrote:
>>> 1) With the short circuit:
>>>
>>> I perform the test you described. It showed that the Kvaser passes from
>>> ERROR-WARNING to ERROR-PASSIVE and then BUS-OFF. But after going to the
>>> state BUS-OFF it comes back to ERROR-WARNING.
>>>
>>>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>>>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>>>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>>>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>>>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>>>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>>>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>>>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>>>   can1  20000088  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>>
>> Why don't we have any rx/tx numbers in the error frame?
> 
> Because the hardware seems to not update the tx/rx_errors_count
> fields :-(

Okay.

>> From the hardware point of view the short circuit and open end tests
>> look good. Please adjust the driver to turn off the CAN interface in
>> case of a bus off if restart_ms is 0.
> 
> And in the case where restart_ms is not 0? Don't I've to put it off so
> and drop the frame?

No, don't drop the frame. restart-ms != 0 means the controller is
automatically restarted after the specified time (if the controller
supports). Or in your and the at91 case, automatically.

> I actually implemeted it as you said and here is what I observed in
> candump output with restart_ms set to 100 ms:
> 
> t0: Short circuit between CAN-H and CAN-L + cansend can1 123#1122
>   can1  2000008C  [8] 00 04 90 00 00 00 00 00   ERRORFRAME
> 	controller-problem{rx-error-warning}
> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
> 	bus-error
>   can1  2000008C  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
> 	controller-problem{rx-error-passive}
> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
> 	bus-error
>   can1  200000C8  [8] 00 00 90 00 00 00 00 00   ERRORFRAME
> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
> 	bus-off
> 	bus-error
> ...
>   can1  2000008C  [8] 00 04 90 00 00 00 00 00   ERRORFRAME
> 	controller-problem{rx-error-warning}
> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
> 	bus-error
>   can1  2000008C  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
> 	controller-problem{rx-error-passive}
> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
> 	bus-error
>   can1  200000C8  [8] 00 00 90 00 00 00 00 00   ERRORFRAME
> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
> 	bus-off
> 	bus-error
> 
> t1: short circuit removed
>   can1  123  [2] 11 22
>   can1  20000100  [8] 00 00 00 00 00 00 00 00   ERRORFRAME
> 	restarted-after-bus-of
> 
> The echo coming before the restart looks weird? No?
> Shouldn't we drop the frame once BUF-OFF is reached?

No, I don't think so. But wait for Wolfgang, here's more into error
handling then me.

> 
>>>>>>> +		if ((priv->can.state == CAN_STATE_ERROR_WARNING) ||
>>>>>>> +		    (priv->can.state == CAN_STATE_ERROR_PASSIVE)) {
>>>>>>> +			cf->data[1] = (txerr > rxerr) ?
>>>>>>> +				CAN_ERR_CRTL_TX_PASSIVE
>>>>>>> +				: CAN_ERR_CRTL_RX_PASSIVE;
>>
>> Please use CAN_ERR_CRTL_RX_WARNING, CAN_ERR_CRTL_TX_WARNING where
>> appropriate.

> Ok. As the hardware doesn't report good values for txerr and rxerr, I'll
> also remove the tests on txerr and rxerr.
> I observed the same behavior with the original driver.
> I asked Kvaser for this problem. I've to wait before their developer is
> back (same for the GPL issue).

Okay.

>>>>>>> +static int kvaser_usb_get_berr_counter(const struct net_device *netdev,
>>>>>>> +				       struct can_berr_counter *bec)
>>>>>>> +{
>>>>>>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
>>>>>>> +
>>>>>>> +	bec->txerr = priv->bec.txerr;
>>>>>>> +	bec->rxerr = priv->bec.rxerr;
>>
>> I think you can copy the struct like this:
>>
>> 	*bec = priv->bec;
> 
> Thanks. I'll remove the function kvaser_usb_get_berr_counter as the
> hardware seems to never report txerr and rxerr.

Sounds reasonable.

BTW: is it possible to update the firmware on these devices?

> I'll look deeper at this driver during the week-end if possible...

Marc

On Thu, Aug 02, 2012 at 01:56:23PM +0200, Marc Kleine-Budde wrote:
> BTW: is it possible to update the firmware on these devices?

Yes it possible. But I don't know how to do it... I never did it.
I saw on their website that they propose a zipfile with new firmwares.
Inside the zipfile there is a tool 'Update.exe' which, I suppose, does
the upgrade.

Kr,

On 08/02/2012 02:16 PM, Olivier Sobrie wrote:
> On Thu, Aug 02, 2012 at 01:56:23PM +0200, Marc Kleine-Budde wrote:
>> BTW: is it possible to update the firmware on these devices?
> 
> Yes it possible. But I don't know how to do it... I never did it.
> I saw on their website that they propose a zipfile with new firmwares.
> Inside the zipfile there is a tool 'Update.exe' which, I suppose, does
> the upgrade.

...on windows only :). If they would be cool, they support dfu.

Marc

On Thu, Aug 02, 2012 at 02:33:56PM +0200, Marc Kleine-Budde wrote:
> On 08/02/2012 02:16 PM, Olivier Sobrie wrote:
> > On Thu, Aug 02, 2012 at 01:56:23PM +0200, Marc Kleine-Budde wrote:
> >> BTW: is it possible to update the firmware on these devices?
> > 
> > Yes it possible. But I don't know how to do it... I never did it.
> > I saw on their website that they propose a zipfile with new firmwares.
> > Inside the zipfile there is a tool 'Update.exe' which, I suppose, does
> > the upgrade.
> 
> ...on windows only :). If they would be cool, they support dfu.

Indeed. I'll check if they are cool ;-)

On 07/31/2012 11:56 AM, Marc Kleine-Budde wrote:
> On 07/30/2012 03:33 PM, Olivier Sobrie wrote:
...

>>>> +static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
>>>> +				const struct kvaser_msg *msg)
>>>> +{
>>>> +	struct can_frame *cf;
>>>> +	struct sk_buff *skb;
>>>> +	struct net_device_stats *stats;
>>>> +	struct kvaser_usb_net_priv *priv;
>>>> +	u8 channel, status, txerr, rxerr;
>>>> +
>>>> +	if (msg->id == CMD_CAN_ERROR_EVENT) {
>>>> +		channel = msg->u.error_event.channel;
>>>> +		status =  msg->u.error_event.status;
>>>> +		txerr = msg->u.error_event.tx_errors_count;
>>>> +		rxerr = msg->u.error_event.rx_errors_count;
>>>> +	} else {
>>>> +		channel = msg->u.chip_state_event.channel;
>>>> +		status =  msg->u.chip_state_event.status;
>>>> +		txerr = msg->u.chip_state_event.tx_errors_count;
>>>> +		rxerr = msg->u.chip_state_event.rx_errors_count;
>>>> +	}
>>>> +
>>>> +	if (channel >= dev->nchannels) {
>>>> +		dev_err(dev->udev->dev.parent,
>>>> +			"Invalid channel number (%d)\n", channel);
>>>> +		return;
>>>> +	}
>>>> +
>>>> +	priv = dev->nets[channel];
>>>> +	stats = &priv->netdev->stats;
>>>> +
>>>> +	skb = alloc_can_err_skb(priv->netdev, &cf);
>>>> +	if (!skb) {
>>>> +		stats->rx_dropped++;
>>>> +		return;
>>>> +	}
>>>> +
>>>> +	if ((status & M16C_STATE_BUS_OFF) ||
>>>> +	    (status & M16C_STATE_BUS_RESET)) {
>>>> +		priv->can.state = CAN_STATE_BUS_OFF;
>>>> +		cf->can_id |= CAN_ERR_BUSOFF;
>>>> +		can_bus_off(priv->netdev);
> 
> you should increment priv->can.can_stats.bus_off

No, already done in can_bus_off():

  http://lxr.free-electrons.com/source/drivers/net/can/dev.c#L439

Wolfgang.
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On 08/02/2012 01:56 PM, Marc Kleine-Budde wrote:
> On 08/02/2012 12:53 PM, Olivier Sobrie wrote:
...
>> I actually implemeted it as you said and here is what I observed in
>> candump output with restart_ms set to 100 ms:
>>
>> t0: Short circuit between CAN-H and CAN-L + cansend can1 123#1122
>>   can1  2000008C  [8] 00 04 90 00 00 00 00 00   ERRORFRAME
>> 	controller-problem{rx-error-warning}
>> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
>> 	bus-error
>>   can1  2000008C  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>> 	controller-problem{rx-error-passive}
>> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
>> 	bus-error
>>   can1  200000C8  [8] 00 00 90 00 00 00 00 00   ERRORFRAME
>> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
>> 	bus-off
>> 	bus-error
>> ...

FYI, the option "-td" nicely shows the timing. I assume that the
"warning->passive->bus-off" sequence repeats because automatic bus-off
is active via ip option "restart-ms xx ms". What I'm missing is the
message "restarted-after-bus-off". Maybe it's not listed here...

>>   can1  2000008C  [8] 00 04 90 00 00 00 00 00   ERRORFRAME
>> 	controller-problem{rx-error-warning}
>> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
>> 	bus-error
>>   can1  2000008C  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
>> 	controller-problem{rx-error-passive}
>> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
>> 	bus-error
>>   can1  200000C8  [8] 00 00 90 00 00 00 00 00   ERRORFRAME
>> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
>> 	bus-off
>> 	bus-error
>>
>> t1: short circuit removed
>>   can1  123  [2] 11 22
>>   can1  20000100  [8] 00 00 00 00 00 00 00 00   ERRORFRAME
>> 	restarted-after-bus-of
>>
>> The echo coming before the restart looks weird? No?

Yes. It should come later.

>> Shouldn't we drop the frame once BUF-OFF is reached?

No.

> No, I don't think so. But wait for Wolfgang, here's more into error
> handling then me.

Looking to your code it's not clear to me how you do recovery from
bus-off (called "restart"). This is usually done via
do_set_mode(CAN_MODE_START), either manually (restart-ms==0) or
automatically (restart-ms>0). Could you please explain how the device
does bus-off recovery? Does the hardware do it automatically? This
should be suppressed if if restart-ms==0 (as Marc already pointed out).

Wolfgang.

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On Sun, Aug 05, 2012 at 10:43:55PM +0200, Wolfgang Grandegger wrote:
> On 08/02/2012 01:56 PM, Marc Kleine-Budde wrote:
> > On 08/02/2012 12:53 PM, Olivier Sobrie wrote:
> ...
> >> I actually implemeted it as you said and here is what I observed in
> >> candump output with restart_ms set to 100 ms:
> >>
> >> t0: Short circuit between CAN-H and CAN-L + cansend can1 123#1122
> >>   can1  2000008C  [8] 00 04 90 00 00 00 00 00   ERRORFRAME
> >> 	controller-problem{rx-error-warning}
> >> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
> >> 	bus-error
> >>   can1  2000008C  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
> >> 	controller-problem{rx-error-passive}
> >> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
> >> 	bus-error
> >>   can1  200000C8  [8] 00 00 90 00 00 00 00 00   ERRORFRAME
> >> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
> >> 	bus-off
> >> 	bus-error
> >> ...
> 
> FYI, the option "-td" nicely shows the timing. I assume that the
> "warning->passive->bus-off" sequence repeats because automatic bus-off
> is active via ip option "restart-ms xx ms". What I'm missing is the
> message "restarted-after-bus-off". Maybe it's not listed here...

Indeed it's missing. Please look at the patch I just sent if it is now
correct or not.

> 
> >>   can1  2000008C  [8] 00 04 90 00 00 00 00 00   ERRORFRAME
> >> 	controller-problem{rx-error-warning}
> >> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
> >> 	bus-error
> >>   can1  2000008C  [8] 00 10 90 00 00 00 00 00   ERRORFRAME
> >> 	controller-problem{rx-error-passive}
> >> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
> >> 	bus-error
> >>   can1  200000C8  [8] 00 00 90 00 00 00 00 00   ERRORFRAME
> >> 	protocol-violation{{tx-recessive-bit-error,error-on-tx}{}}
> >> 	bus-off
> >> 	bus-error
> >>
> >> t1: short circuit removed
> >>   can1  123  [2] 11 22
> >>   can1  20000100  [8] 00 00 00 00 00 00 00 00   ERRORFRAME
> >> 	restarted-after-bus-of
> >>
> >> The echo coming before the restart looks weird? No?
> 
> Yes. It should come later.

Ok I've to change this.

> 
> >> Shouldn't we drop the frame once BUF-OFF is reached?
> 
> No.

Ok.

> 
> > No, I don't think so. But wait for Wolfgang, here's more into error
> > handling then me.
> 
> Looking to your code it's not clear to me how you do recovery from
> bus-off (called "restart"). This is usually done via
> do_set_mode(CAN_MODE_START), either manually (restart-ms==0) or
> automatically (restart-ms>0). Could you please explain how the device
> does bus-off recovery? Does the hardware do it automatically? This
> should be suppressed if if restart-ms==0 (as Marc already pointed out).

The hardware automatically recovers from BUS-OFF if it isn't stopped.
In the second version of the patch I just sent, I put the device off if
restart-ms == 0.

Thanks,