snd_pcm_sync_stop
snd_pcm_sync_stop(substream, false);
void snd_pcm_sync_stop(struct snd_pcm_substream *substream, bool sync_irq);
snd_pcm_sync_stop(substream, false);
snd_pcm_sync_stop(substream, true);
snd_pcm_sync_stop(substream, true);
snd_pcm_sync_stop(substream, true);