Re: [PATCH net] can: rockchip_canfd: stop bus-off restart before closing the device

[Marc Kleine-Budde]

On 13.10.2026 11:22:37, Cunhao Lu wrote:
> The close path cancels restart_work after freeing the IRQ and stopping
> hardware. A queued bus-off restart can therefore enable the controller
> and interrupts after teardown. It can also restart timestamp work before
> runtime suspend.
>
> Serialize restart with the close transition using a mutex. Mark the
> device closing and mask its interrupts before synchronizing the IRQ.
> Release the mutex before cancelling restart_work, so a queued restart
> can observe the closing state without deadlocking.
>
> Exclude the IRQ handler while reinitializing the hardware on restart.
> Do not disable the shared IRQ line while waiting for work to finish.
>
> Fixes: ff60bfbaf67f ("can: rockchip_canfd: add driver for Rockchip CAN-FD controller")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Cunhao Lu <1579567540@xxxxxx>

AFAICS this is a systematic problem and should IMHO not worked around in
one driver only.

netif_running() tests __LINK_STATE_START, which is removed in
__dev_close_many() prior to calling the driver's ndo_stop().

Can we make use of netif_running() prior to calling do_set_mode(dev,
CAN_MODE_START)? from can_restart()?

can_bus_off() should not schedule_delayed_work() if !netif_running().

We still have to call cancel_delayed_work_sync(&priv->can.restart_work)
from each driver, though.

What do you think?

Marc

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