can: dev: fix deadlock reported after bus-off

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>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 5261751f6bd4..5f5270941ba0 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -32,6 +32,7 @@ enum can_mode {
  * CAN common private data
  */
 struct can_priv {
+        struct net_device *dev;
         struct can_device_stats can_stats;
 
         struct can_bittiming bittiming, data_bittiming;
@@ -47,7 +48,7 @@ struct can_priv {
         u32 ctrlmode_static;    /* static enabled options for driver/hardware */
 
         int restart_ms;
-        struct timer_list restart_timer;
+        struct delayed_work restart_work;
 
         int (*do_set_bittiming)(struct net_device *dev);
         int (*do_set_data_bittiming)(struct net_device *dev);