diff options
| author | Sergei Miroshnichenko <sergeimir@emcraft.com> | 2016-09-07 16:51:12 +0300 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-04-11 10:58:57 +0200 |
| commit | 6d9fd9bb0ea894d1fafc4db05cb2ba7b9fafa6f9 (patch) | |
| tree | f67ea2ae878c5efd8a8d59391bc95f59969c22f1 /drivers/net/can | |
| parent | 9a5b49592d8c3d72ac321a363efde5d64cf4d274 (diff) | |
can: dev: fix deadlock reported after bus-off
commit 9abefcb1aaa58b9d5aa40a8bb12c87d02415e4c8 upstream.
A timer was used to restart after the bus-off state, leading to a
relatively large can_restart() executed in an interrupt context,
which in turn sets up pinctrl. When this happens during system boot,
there is a high probability of grabbing the pinctrl_list_mutex,
which is locked already by the probe() of other device, making the
kernel suspect a deadlock condition [1].
To resolve this issue, the restart_timer is replaced by a delayed
work.
[1] https://github.com/victronenergy/venus/issues/24
Signed-off-by: Sergei Miroshnichenko <sergeimir@emcraft.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Diffstat (limited to 'drivers/net/can')
| -rw-r--r-- | drivers/net/can/dev.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c index 464e5f66b..284d751ea 100644 --- a/drivers/net/can/dev.c +++ b/drivers/net/can/dev.c @@ -22,6 +22,7 @@ #include <linux/slab.h> #include <linux/netdevice.h> #include <linux/if_arp.h> +#include <linux/workqueue.h> #include <linux/can.h> #include <linux/can/dev.h> #include <linux/can/skb.h> @@ -394,9 +395,8 @@ EXPORT_SYMBOL_GPL(can_free_echo_skb); /* * CAN device restart for bus-off recovery */ -static void can_restart(unsigned long data) +static void can_restart(struct net_device *dev) { - struct net_device *dev = (struct net_device *)data; struct can_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; struct sk_buff *skb; @@ -436,6 +436,14 @@ restart: netdev_err(dev, "Error %d during restart", err); } +static void can_restart_work(struct work_struct *work) +{ + struct delayed_work *dwork = to_delayed_work(work); + struct can_priv *priv = container_of(dwork, struct can_priv, restart_work); + + can_restart(priv->dev); +} + int can_restart_now(struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); @@ -449,8 +457,8 @@ int can_restart_now(struct net_device *dev) if (priv->state != CAN_STATE_BUS_OFF) return -EBUSY; - /* Runs as soon as possible in the timer context */ - mod_timer(&priv->restart_timer, jiffies); + cancel_delayed_work_sync(&priv->restart_work); + can_restart(dev); return 0; } @@ -472,8 +480,8 @@ void can_bus_off(struct net_device *dev) priv->can_stats.bus_off++; if (priv->restart_ms) - mod_timer(&priv->restart_timer, - jiffies + (priv->restart_ms * HZ) / 1000); + schedule_delayed_work(&priv->restart_work, + msecs_to_jiffies(priv->restart_ms)); } EXPORT_SYMBOL_GPL(can_bus_off); @@ -556,6 +564,7 @@ struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max) return NULL; priv = netdev_priv(dev); + priv->dev = dev; if (echo_skb_max) { priv->echo_skb_max = echo_skb_max; @@ -565,7 +574,7 @@ struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max) priv->state = CAN_STATE_STOPPED; - init_timer(&priv->restart_timer); + INIT_DELAYED_WORK(&priv->restart_work, can_restart_work); return dev; } @@ -599,8 +608,6 @@ int open_candev(struct net_device *dev) if (!netif_carrier_ok(dev)) netif_carrier_on(dev); - setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev); - return 0; } EXPORT_SYMBOL_GPL(open_candev); @@ -615,7 +622,7 @@ void close_candev(struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); - del_timer_sync(&priv->restart_timer); + cancel_delayed_work_sync(&priv->restart_work); can_flush_echo_skb(dev); } EXPORT_SYMBOL_GPL(close_candev); |