+static int snd_compress_wait_for_drain(struct snd_compr_stream *stream)
+{
+ int ret;
+
+ /*
+ * We are called with lock held. So drop the lock while we wait for
+ * drain complete notfication from the driver
+ *
+ * It is expected that driver will notify the drain completion and then
+ * stream will be moved to SETUP state, even if draining resulted in an
+ * error. We can trigger next track after this.
+ */
+ stream->runtime->state = SNDRV_PCM_STATE_DRAINING;
+ mutex_unlock(&stream->device->lock);
+
+ /* we wait for drain to complete here, drain can return when
+ * interruption occurred, wait returned error or success.
+ * For the first two cases we don't do anything different here and
+ * return after waking up
+ */
+
+ ret = wait_event_interruptible(stream->runtime->sleep,
+ (stream->runtime->state != SNDRV_PCM_STATE_DRAINING));
+ if (ret == -ERESTARTSYS)
+ pr_debug("wait aborted by a signal");
+ else if (ret)
+ pr_debug("wait for drain failed with %d\n", ret);
+
+
+ wake_up(&stream->runtime->sleep);
+ mutex_lock(&stream->device->lock);
+
+ return ret;
+}
+