static int snd_pcm_do_stop(struct snd_pcm_substream *substream, int state)
{
if (substream->runtime->trigger_master == substream &&
snd_pcm_running(substream))
substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_STOP);
return 0; /* unconditonally stop all substreams */ }