SND_COMPR_TRIGGER_PARTIAL_DRAIN
retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_PARTIAL_DRAIN);
case SND_COMPR_TRIGGER_PARTIAL_DRAIN:
case SND_COMPR_TRIGGER_PARTIAL_DRAIN:
case SND_COMPR_TRIGGER_PARTIAL_DRAIN:
if (cmd == SND_COMPR_TRIGGER_PARTIAL_DRAIN ||
case SND_COMPR_TRIGGER_PARTIAL_DRAIN: