ALSA: timer: Sync timer deletion at closing the system timer (f146357f) · Commits · e / devices / android_kernel_fairphone_FP3

ALSA timer core framework has no sync point at stopping because it's called inside the spinlock. Thus we need a sync point at close for avoiding the stray timer task. This is simply done by implementing the close callback just calling del_timer_sync(). (It's harmless to call it unconditionally, as the core timer itself cares of the already deleted timer instance.) Signed-off-by:

Takashi Iwai <tiwai@suse.de>

sound/core/timer.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -1058,11 +1058,21 @@ static int snd_timer_s_stop(struct snd_timer * timer)
		return 0;
		}

		static int snd_timer_s_close(struct snd_timer *timer)
		{
		struct snd_timer_system_private *priv;

		priv = (struct snd_timer_system_private *)timer->private_data;
		del_timer_sync(&priv->tlist);
		return 0;
		}

		static struct snd_timer_hardware snd_timer_system =
		{
		.flags = SNDRV_TIMER_HW_FIRST \| SNDRV_TIMER_HW_TASKLET,
		.resolution = 1000000000L / HZ,
		.ticks = 10000000L,
		.close = snd_timer_s_close,
		.start = snd_timer_s_start,
		.stop = snd_timer_s_stop
		};