Re: [PATCH] ALSA: mtpav: shut down output timer before card teardown
Takashi Iwai <[email protected]>
| Newsgroups | org.kernel.vger.linux-sound,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
On Thu, 20 Aug 2026 13:27:49 +0200,
Runyu Xiao wrote:
>
> snd_mtpav_output_timer() rearms chip->timer while holding
> chip->spinlock and accesses the card-private mtpav state.
>
> snd_mtpav_free() currently takes the same lock and calls
> timer_delete() when the timer is active. This only removes a
> pending timer; it does not wait for a callback that is already
> running and does not prevent the callback from rearming the timer.
>
> A callback running on another CPU can therefore continue after
> snd_mtpav_free() releases the lock and access the card-private
> state while the card is being torn down. It can also rearm the
> timer after timer_delete() has returned.
>
> Call timer_shutdown_sync() without holding chip->spinlock. This
> waits for any running callback to finish and prevents further
> rearming before the card-private mtpav state is released.
>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Runyu Xiao <[email protected]>
Thanks, applied now.
Takashi