ALSA: pcm: Add snd_pcm_stop_xrun() helper

Add a new helper function snd_pcm_stop_xrun() to the standard sequnce
lock/snd_pcm_stop(XRUN)/unlock by a single call, and replace the
existing open codes with this helper.

The function checks the PCM running state to prevent setting the wrong
state, too, for more safety.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 23 insertions, 0 deletions

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index dfb5031..a3d1221 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -1098,6 +1098,29 @@ int snd_pcm_drain_done(struct snd_pcm_substream *substream)
 				     SNDRV_PCM_STATE_SETUP);
 }
 
+/**
+ * snd_pcm_stop_xrun - stop the running streams as XRUN
+ * @substream: the PCM substream instance
+ * @state: PCM state after stopping the stream
+ *
+ * This stops the given running substream (and all linked substreams) as XRUN.
+ * Unlike snd_pcm_stop(), this function takes the substream lock by itself.
+ *
+ * Return: Zero if successful, or a negative error code.
+ */
+int snd_pcm_stop_xrun(struct snd_pcm_substream *substream)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	snd_pcm_stream_lock_irqsave(substream, flags);
+	if (snd_pcm_running(substream))
+		ret = snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
+	snd_pcm_stream_unlock_irqrestore(substream, flags);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(snd_pcm_stop_xrun);
+
 /*
  * pause callbacks
  */