| Message ID | 1320313675-30749-3-git-send-email-mkl@pengutronix.de |
|---|---|
| State | Deferred, archived |
| Delegated to: | David Miller |
| Headers | show |
On 11/03/2011 10:47 AM, Marc Kleine-Budde wrote: > From: Reuben Dowle <Reuben.Dowle@navico.com> > > Currently the flexcan driver uses hardware local echo. This blindly > echos all transmitted frames to all receiving sockets, regardless what > CAN_RAW_RECV_OWN_MSGS and CAN_RAW_LOOPBACK are set to. > > This patch now submits transmitted frames to be echoed in the transmit > complete interrupt, preserving the reference to the sending > socket. This allows the can protocol to correctly handle the local > echo. > > Further this patch moves tx_bytes statistic accounting into the tx_complete > handler. > > Signed-off-by: Reuben Dowle <reuben.dowle@navico.com> > [mkl: move tx_bytes accounting into tx_complete handler; cleanups] > Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> > --- A changelog would be nice :) Since v1 (Reuben's original version): - wrap patch description to 80 lines - remove can_free_echo_skb() from flexcan_chip_start() not needed as Reuben pointed out - remove comments about IFF_ECHO; see patch description for this - closed potential race condition in flexcan_start_xmit() first call can_put_echo_skb(), then trigger xmit - moved tx_bytes accounting to tx_complete handler; make use of new can_get_echo_skb() Marc
On 03.11.2011 10:47, Marc Kleine-Budde wrote: > @@ -609,9 +605,10 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id) > > /* transmission complete interrupt */ > if (reg_iflag1 & (1 << FLEXCAN_TX_BUF_ID)) { > - /* tx_bytes is incremented in flexcan_start_xmit */ > + stats->tx_bytes += can_get_echo_skb(dev, 0); > stats->tx_packets++; > flexcan_write((1 << FLEXCAN_TX_BUF_ID), ®s->iflag1); > + can_get_echo_skb(dev, 0); > netif_wake_queue(dev); > } What's the reason for the second can_get_echo_skb() here? IIRC the skb is already netif_rx'ed and consumed by the first attempt. Regards, Oliver -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 11/03/2011 11:03 AM, Oliver Hartkopp wrote: > On 03.11.2011 10:47, Marc Kleine-Budde wrote: > >> @@ -609,9 +605,10 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id) >> >> /* transmission complete interrupt */ >> if (reg_iflag1 & (1 << FLEXCAN_TX_BUF_ID)) { >> - /* tx_bytes is incremented in flexcan_start_xmit */ >> + stats->tx_bytes += can_get_echo_skb(dev, 0); >> stats->tx_packets++; >> flexcan_write((1 << FLEXCAN_TX_BUF_ID), ®s->iflag1); >> + can_get_echo_skb(dev, 0); >> netif_wake_queue(dev); >> } > > > What's the reason for the second can_get_echo_skb() here? doh! Marc
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index e023379..ea7b668 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -269,7 +269,6 @@ static int flexcan_get_berr_counter(const struct net_device *dev, static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev) { const struct flexcan_priv *priv = netdev_priv(dev); - struct net_device_stats *stats = &dev->stats; struct flexcan_regs __iomem *regs = priv->base; struct can_frame *cf = (struct can_frame *)skb->data; u32 can_id; @@ -299,14 +298,11 @@ static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev) flexcan_write(data, ®s->cantxfg[FLEXCAN_TX_BUF_ID].data[1]); } + can_put_echo_skb(skb, dev, 0); + flexcan_write(can_id, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_id); flexcan_write(ctrl, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl); - kfree_skb(skb); - - /* tx_packets is incremented in flexcan_irq */ - stats->tx_bytes += cf->can_dlc; - return NETDEV_TX_OK; } @@ -609,9 +605,10 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id) /* transmission complete interrupt */ if (reg_iflag1 & (1 << FLEXCAN_TX_BUF_ID)) { - /* tx_bytes is incremented in flexcan_start_xmit */ + stats->tx_bytes += can_get_echo_skb(dev, 0); stats->tx_packets++; flexcan_write((1 << FLEXCAN_TX_BUF_ID), ®s->iflag1); + can_get_echo_skb(dev, 0); netif_wake_queue(dev); } @@ -697,12 +694,13 @@ static int flexcan_chip_start(struct net_device *dev) * only supervisor access * enable warning int * choose format C + * disable local echo * */ reg_mcr = flexcan_read(®s->mcr); reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT | FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN | - FLEXCAN_MCR_IDAM_C; + FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_SRX_DIS; dev_dbg(dev->dev.parent, "%s: writing mcr=0x%08x", __func__, reg_mcr); flexcan_write(reg_mcr, ®s->mcr); @@ -970,7 +968,7 @@ static int __devinit flexcan_probe(struct platform_device *pdev) goto failed_map; } - dev = alloc_candev(sizeof(struct flexcan_priv), 0); + dev = alloc_candev(sizeof(struct flexcan_priv), 1); if (!dev) { err = -ENOMEM; goto failed_alloc; @@ -978,7 +976,7 @@ static int __devinit flexcan_probe(struct platform_device *pdev) dev->netdev_ops = &flexcan_netdev_ops; dev->irq = irq; - dev->flags |= IFF_ECHO; /* we support local echo in hardware */ + dev->flags |= IFF_ECHO; priv = netdev_priv(dev); priv->can.clock.freq = clock_freq;