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[3.8.y.z,extended,stable] Patch "USB: mos7840: fix device-type detection" has been added to staging queue

Message ID 1376528722-1111-1-git-send-email-kamal@canonical.com
State New
Headers show

Commit Message

Kamal Mostafa Aug. 15, 2013, 1:05 a.m. UTC
This is a note to let you know that I have just added a patch titled

    USB: mos7840: fix device-type detection

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.7.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

From b6e3a62fed8f728834cf4bad5207fce6b0d33334 Mon Sep 17 00:00:00 2001
From: Johan Hovold <jhovold@gmail.com>
Date: Fri, 26 Jul 2013 11:55:18 +0200
Subject: USB: mos7840: fix device-type detection

commit 40c24f2893ba0ba7df485871f6aac0c197ceef5b upstream.

Fix race in device-type detection introduced by commit 0eafe4de ("USB:
serial: mos7840: add support for MCS7810 devices") which used a static
variable to hold the device type.

Move type detection to probe and use serial data to store the device
type.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/usb/serial/mos7840.c | 75 +++++++++++++++++++++-----------------------
 1 file changed, 35 insertions(+), 40 deletions(-)

--
1.8.1.2
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Patch

diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index eab52f6..343a179 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -187,8 +187,6 @@  enum mos7840_flag {
 	MOS7840_FLAG_CTRL_BUSY,
 };

-static int device_type;
-
 static const struct usb_device_id id_table[] = {
 	{USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7840)},
 	{USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7820)},
@@ -867,18 +865,6 @@  static void mos7840_bulk_out_data_callback(struct urb *urb)
 /************************************************************************/
 /*       D R I V E R  T T Y  I N T E R F A C E  F U N C T I O N S       */
 /************************************************************************/
-#ifdef MCSSerialProbe
-static int mos7840_serial_probe(struct usb_serial *serial,
-				const struct usb_device_id *id)
-{
-
-	/*need to implement the mode_reg reading and updating\
-	   structures usb_serial_ device_type\
-	   (i.e num_ports, num_bulkin,bulkout etc) */
-	/* Also we can update the changes  attach */
-	return 1;
-}
-#endif

 /*****************************************************************************
  * mos7840_open
@@ -2333,38 +2319,48 @@  static int mos7810_check(struct usb_serial *serial)
 	return 0;
 }

-static int mos7840_calc_num_ports(struct usb_serial *serial)
+static int mos7840_probe(struct usb_serial *serial,
+				const struct usb_device_id *id)
 {
-	__u16 data = 0x00;
+	u16 product = serial->dev->descriptor.idProduct;
 	u8 *buf;
-	int mos7840_num_ports;
+	int device_type;
+
+	if (product == MOSCHIP_DEVICE_ID_7810 ||
+		product == MOSCHIP_DEVICE_ID_7820) {
+		device_type = product;
+		goto out;
+	}

 	buf = kzalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
-	if (buf) {
-		usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+	if (!buf)
+		return -ENOMEM;
+
+	usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
 			MCS_RDREQ, MCS_RD_RTYPE, 0, GPIO_REGISTER, buf,
 			VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
-		data = *buf;
-		kfree(buf);
-	}

-	if (serial->dev->descriptor.idProduct == MOSCHIP_DEVICE_ID_7810 ||
-		serial->dev->descriptor.idProduct == MOSCHIP_DEVICE_ID_7820) {
-		device_type = serial->dev->descriptor.idProduct;
-	} else {
-		/* For a MCS7840 device GPIO0 must be set to 1 */
-		if ((data & 0x01) == 1)
-			device_type = MOSCHIP_DEVICE_ID_7840;
-		else if (mos7810_check(serial))
-			device_type = MOSCHIP_DEVICE_ID_7810;
-		else
-			device_type = MOSCHIP_DEVICE_ID_7820;
-	}
+	/* For a MCS7840 device GPIO0 must be set to 1 */
+	if (buf[0] & 0x01)
+		device_type = MOSCHIP_DEVICE_ID_7840;
+	else if (mos7810_check(serial))
+		device_type = MOSCHIP_DEVICE_ID_7810;
+	else
+		device_type = MOSCHIP_DEVICE_ID_7820;
+
+	kfree(buf);
+out:
+	usb_set_serial_data(serial, (void *)device_type);
+
+	return 0;
+}
+
+static int mos7840_calc_num_ports(struct usb_serial *serial)
+{
+	int device_type = (int)usb_get_serial_data(serial);
+	int mos7840_num_ports;

 	mos7840_num_ports = (device_type >> 4) & 0x000F;
-	serial->num_bulk_in = mos7840_num_ports;
-	serial->num_bulk_out = mos7840_num_ports;
-	serial->num_ports = mos7840_num_ports;

 	return mos7840_num_ports;
 }
@@ -2372,6 +2368,7 @@  static int mos7840_calc_num_ports(struct usb_serial *serial)
 static int mos7840_port_probe(struct usb_serial_port *port)
 {
 	struct usb_serial *serial = port->serial;
+	int device_type = (int)usb_get_serial_data(serial);
 	struct moschip_port *mos7840_port;
 	int status;
 	int pnum;
@@ -2630,9 +2627,7 @@  static struct usb_serial_driver moschip7840_4port_device = {
 	.throttle = mos7840_throttle,
 	.unthrottle = mos7840_unthrottle,
 	.calc_num_ports = mos7840_calc_num_ports,
-#ifdef MCSSerialProbe
-	.probe = mos7840_serial_probe,
-#endif
+	.probe = mos7840_probe,
 	.ioctl = mos7840_ioctl,
 	.set_termios = mos7840_set_termios,
 	.break_ctl = mos7840_break,