Hi Takashi, Sorry for interrupt you again after such a long time. I just notice there was an old patch posted[1] from you that made pcm pointer() and trigger() callbacks could being able to be executed under non-atomic context, by using mutex instead of spin_lock_irq(). I find several similar deadlocks like this one on other places(inside pointer() and trigger() callbacks and being interrupted by hardirq), I am confusing whether they could be real deadlocks, as if these callbacks are executed under non-atomic context then they could be real problem. Thanks much if you are available to reply, Chengfeng [1] https://patchwork.kernel.org/project/alsa-devel/patch/1409572832-32553-2-git-send-email-tiwai@xxxxxxx/
