ASoC: SOF: pcm: Add an option to skip platform trigger during stop

In the case of IPC4, a pipeline is only paused during STOP/PAUSE/SUSPEND
triggers and the FW keeps the host DMA running when a pipeline is
paused. The start/stop tests iterate through STOP/START triggers without
involving a hw_free. This means that the pipeline state will only toggle
between PAUSED (during the STOP trigger) and RUNNING (during the START
trigger). So this test should be treated in the same way as a
PAUSE_PUSH/PAUSE_RELEASE test and the DMA should be kept running when
toggling the pipeline states between PAUSED and RUNNING.

Since there is no way to tell if a STOP trigger will be followed by hw_free
or not, this patch proposes to always skip DMA stop during the STOP trigger
and handle it later during hw_free. Introduce a new flag in struct
sof_ipc_pcm_ops, delayed_platform_trigger, that will be used to ensure that
the host DMA will not be stopped during the STOP/PAUSE/RELEASE triggers
and set it for IPC4. The platform_trigger call to stop the DMA will be
invoked during PCM hw_free instead when the pipeline is reset.

Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20230420114137.27613-3-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 14 insertions, 8 deletions

diff --git a/sound/soc/sof/sof-audio.c b/sound/soc/sof/sof-audio.c
index 7651644fcd62..1cbda595c518 100644
--- a/sound/soc/sof/sof-audio.c
+++ b/sound/soc/sof/sof-audio.c
@@ -805,16 +805,22 @@ int sof_pcm_stream_free(struct snd_sof_dev *sdev, struct snd_pcm_substream *subs
 	const struct sof_ipc_pcm_ops *pcm_ops = sof_ipc_get_ops(sdev, pcm);
 	int ret;
 
-	/* Send PCM_FREE IPC to reset pipeline */
-	if (pcm_ops && pcm_ops->hw_free && spcm->prepared[substream->stream]) {
-		ret = pcm_ops->hw_free(sdev->component, substream);
-		if (ret < 0)
-			return ret;
-	}
+	if (spcm->prepared[substream->stream]) {
+		/* stop DMA first if needed */
+		if (pcm_ops && pcm_ops->platform_stop_during_hw_free)
+			snd_sof_pcm_platform_trigger(sdev, substream, SNDRV_PCM_TRIGGER_STOP);
+
+		/* Send PCM_FREE IPC to reset pipeline */
+		if (pcm_ops && pcm_ops->hw_free) {
+			ret = pcm_ops->hw_free(sdev->component, substream);
+			if (ret < 0)
+				return ret;
+		}
 
-	spcm->prepared[substream->stream] = false;
+		spcm->prepared[substream->stream] = false;
+	}
 
-	/* stop the DMA */
+	/* reset the DMA */
 	ret = snd_sof_pcm_platform_hw_free(sdev, substream);
 	if (ret < 0)
 		return ret;