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| author | Marc Kleine-Budde <mkl@pengutronix.de> | 2023-10-05 21:34:37 +0200 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2023-10-05 21:34:37 +0200 |
| commit | 2f0382a7590ed65ef6a4336aace0f30814e24dc1 (patch) | |
| tree | 5569cd7fa8f9cbce1ae030fd35508c46f60c1e1a /drivers/net/can | |
| parent | 3b9333493b5fa69f2dce8eb96bbef32df1b65c4a (diff) | |
| parent | 6411959c10fe917288cbb1038886999148560057 (diff) | |
Merge patch series "can: dev: fix can_restart() and replace BUG_ON() by error handling"
Marc Kleine-Budde <mkl@pengutronix.de> says:
There are 2 BUG_ON() in the CAN dev helpers. During the update/test of
the at91_can driver to rx-offload the one in can_restart() was
triggered, due to a race condition in can_restart() and a hardware
limitation of the at91_can IP core.
This series fixes the race condition, replaces BUG_ON() with an error
message, and does some cleanup. Finally, the BUG_ON() in
can_put_echo_skb() is also replaced with error handling.
Changes in v2:
- 4/5: move "Restarted" debug message and stats after successful restart (Thanks Vincent)
- Link to v1: https://lore.kernel.org/all/20231004-can-dev-fix-can-restart-v1-0-2e52899eaaf5@pengutronix.de
Link: https://lore.kernel.org/all/20231005-can-dev-fix-can-restart-v2-0-91b5c1fd922c@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can')
| -rw-r--r-- | drivers/net/can/dev/dev.c | 29 | ||||
| -rw-r--r-- | drivers/net/can/dev/skb.c | 6 |
2 files changed, 19 insertions, 16 deletions
diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c index 7f9334a8af50..82b12902fc35 100644 --- a/drivers/net/can/dev/dev.c +++ b/drivers/net/can/dev/dev.c @@ -132,7 +132,8 @@ static void can_restart(struct net_device *dev) struct can_frame *cf; int err; - BUG_ON(netif_carrier_ok(dev)); + if (netif_carrier_ok(dev)) + netdev_err(dev, "Attempt to restart for bus-off recovery, but carrier is OK?\n"); /* No synchronization needed because the device is bus-off and * no messages can come in or go out. @@ -141,23 +142,21 @@ static void can_restart(struct net_device *dev) /* send restart message upstream */ skb = alloc_can_err_skb(dev, &cf); - if (!skb) - goto restart; - - cf->can_id |= CAN_ERR_RESTARTED; - - netif_rx(skb); - -restart: - netdev_dbg(dev, "restarted\n"); - priv->can_stats.restarts++; + if (skb) { + cf->can_id |= CAN_ERR_RESTARTED; + netif_rx(skb); + } /* Now restart the device */ - err = priv->do_set_mode(dev, CAN_MODE_START); - netif_carrier_on(dev); - if (err) - netdev_err(dev, "Error %d during restart", err); + err = priv->do_set_mode(dev, CAN_MODE_START); + if (err) { + netdev_err(dev, "Restart failed, error %pe\n", ERR_PTR(err)); + netif_carrier_off(dev); + } else { + netdev_dbg(dev, "Restarted\n"); + priv->can_stats.restarts++; + } } static void can_restart_work(struct work_struct *work) diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c index f6d05b3ef59a..3ebd4f779b9b 100644 --- a/drivers/net/can/dev/skb.c +++ b/drivers/net/can/dev/skb.c @@ -49,7 +49,11 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, { struct can_priv *priv = netdev_priv(dev); - BUG_ON(idx >= priv->echo_skb_max); + if (idx >= priv->echo_skb_max) { + netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n", + __func__, idx, priv->echo_skb_max); + return -EINVAL; + } /* check flag whether this packet has to be looped back */ if (!(dev->flags & IFF_ECHO) || |