static int snd_compr_partial_drain(struct snd_compr_stream *stream)
{
	int retval;
	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
		return -EPERM;
	/* stream can be drained only when next track has been signalled */
	if (stream->next_track == false)
		return -EPERM;

	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_PARTIAL_DRAIN);
	if (retval) {
		pr_debug("Partial drain returned failure\n");
		wake_up(&stream->runtime->sleep);
		return retval;
	}

	stream->next_track = false;
	return snd_compress_wait_for_drain(stream);
}

Unknown