[PATCH] ASoC: SOF: ipc4-topology: Implement tear_down_all_pipelines callback

[Peter Ujfalusi]

During system suspend there is a chance that the running stream undergo
an xrun and instead of the expected SNDRV_PCM_TRIGGER_SUSPEND trigger
we will receive SNDRV_PCM_TRIGGER_STOP.

The handling of SUSPEND and STOP triggers differ that case of the later
the sof_pcm_stream_free() will be called with free_widget_list = false.
But we must make sure that all active widgets and streams are free before
entering suspend in order to be able to resume without error.

We can utilize the tear_down_all_pipelines to put the system to an expected
state and to fix the suspend/resume error.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi at linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao at linux.intel.com>
---
 sound/soc/sof/ipc4-topology.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/sound/soc/sof/ipc4-topology.c b/sound/soc/sof/ipc4-topology.c
index ab85dde4303b..c31b7f065c1d 100644
--- a/sound/soc/sof/ipc4-topology.c
+++ b/sound/soc/sof/ipc4-topology.c
@@ -1813,6 +1813,39 @@ static int sof_ipc4_dai_get_clk(struct snd_sof_dev *sdev, struct snd_sof_dai *da
 	return -EINVAL;
 }
 
+static int sof_ipc4_tear_down_all_pipelines(struct snd_sof_dev *sdev, bool verify)
+{
+	struct snd_sof_pcm *spcm;
+	int dir, ret;
+
+	/*
+	 * This function is called during system suspend, we need to make sure
+	 * that all streams have been freed up.
+	 * Freeing might have been skipped when xrun happened just at the start
+	 * of the suspend and it sent a SNDRV_PCM_TRIGGER_STOP to the active
+	 * stream. This will call sof_pcm_stream_free() with
+	 * free_widget_list = false which will leave the kernel and firmware out
+	 * of sync during suspend/resume.
+	 *
+	 * This will also make sure that paused streams handled correctly.
+	 */
+	list_for_each_entry(spcm, &sdev->pcm_list, list) {
+		for_each_pcm_streams(dir) {
+			struct snd_pcm_substream *substream = spcm->stream[dir].substream;
+
+			if (!substream || !substream->runtime)
+				continue;
+
+			if (spcm->stream[dir].list) {
+				ret = sof_pcm_stream_free(sdev, substream, spcm, dir, true);
+				if (ret < 0)
+					return ret;
+			}
+		}
+	}
+	return 0;
+}
+
 static enum sof_tokens host_token_list[] = {
 	SOF_COMP_TOKENS,
 	SOF_AUDIO_FMT_NUM_TOKENS,
@@ -1913,4 +1946,5 @@ const struct sof_ipc_tplg_ops ipc4_tplg_ops = {
 	.dai_config = sof_ipc4_dai_config,
 	.parse_manifest = sof_ipc4_parse_manifest,
 	.dai_get_clk = sof_ipc4_dai_get_clk,
+	.tear_down_all_pipelines = sof_ipc4_tear_down_all_pipelines,
 };
-- 
2.38.1