ASoC: SOF: pcm/Intel: Pause-resume improvements for

Merge series from Peter Ujfalusi <peter.ujfalusi@linux.intel.com>:

Last minute patch for correct the pasue/resume operation with IPC4.  The
issues are hardto reproduce and needs extended stress testing to be hit,
in which case the audio breaks due to DMA errors.

sound/soc/sof/intel/hda-stream.c

@@ -337,7 +337,13 @@ int hda_dsp_stream_trigger(struct snd_sof_dev *sdev,
 	/* cmd must be for audio stream */
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		if (!sdev->dspless_mode_selected)
+			break;
+		fallthrough;
 	case SNDRV_PCM_TRIGGER_START:
+		if (hstream->running)
+			break;
+
 		snd_sof_dsp_update_bits(sdev, HDA_DSP_HDA_BAR, SOF_HDA_INTCTL,
 					1 << hstream->index,
 					1 << hstream->index);
@@ -360,8 +366,11 @@ int hda_dsp_stream_trigger(struct snd_sof_dev *sdev,
 			hstream->running = true;
 
 		break;
-	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		if (!sdev->dspless_mode_selected)
+			break;
+		fallthrough;
+	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_STOP:
 		snd_sof_dsp_update_bits(sdev, HDA_DSP_HDA_BAR,
 					sd_offset,

sound/soc/sof/ipc4-pcm.c

@@ -836,5 +836,6 @@ const struct sof_ipc_pcm_ops ipc4_pcm_ops = {
 	.pcm_setup = sof_ipc4_pcm_setup,
 	.pcm_free = sof_ipc4_pcm_free,
 	.delay = sof_ipc4_pcm_delay,
-	.ipc_first_on_start = true
+	.ipc_first_on_start = true,
+	.platform_stop_during_hw_free = true,
 };

sound/soc/sof/pcm.c

@@ -211,16 +211,22 @@ static int sof_pcm_hw_free(struct snd_soc_component *component,
 	dev_dbg(component->dev, "pcm: free stream %d dir %d\n",
 		spcm->pcm.pcm_id, substream->stream);
 
-	/* free PCM in the DSP */
-	if (pcm_ops && pcm_ops->hw_free && spcm->prepared[substream->stream]) {
-		ret = pcm_ops->hw_free(component, substream);
-		if (ret < 0)
-			err = 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);
+
+		/* free PCM in the DSP */
+		if (pcm_ops && pcm_ops->hw_free) {
+			ret = pcm_ops->hw_free(component, substream);
+			if (ret < 0)
+				err = ret;
+		}
 
 		spcm->prepared[substream->stream] = false;
 	}
 
-	/* stop DMA */
+	/* reset DMA */
 	ret = snd_sof_pcm_platform_hw_free(sdev, substream);
 	if (ret < 0) {
 		dev_err(component->dev, "error: platform hw free failed\n");
@@ -362,8 +368,9 @@ static int sof_pcm_trigger(struct snd_soc_component *component,
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 	case SNDRV_PCM_TRIGGER_STOP:
-		/* invoke platform trigger to stop DMA even if pcm_ops failed */
-		snd_sof_pcm_platform_trigger(sdev, substream, cmd);
+		/* invoke platform trigger to stop DMA even if pcm_ops isn't set or if it failed */
+		if (!pcm_ops || (pcm_ops && !pcm_ops->platform_stop_during_hw_free))
+			snd_sof_pcm_platform_trigger(sdev, substream, cmd);
 		break;
 	default:
 		break;

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;

sound/soc/sof/sof-audio.h

@@ -108,6 +108,11 @@ struct snd_sof_dai_config_data {
  *				 STOP pcm trigger
  * @ipc_first_on_start: Send IPC before invoking platform trigger during
  *				START/PAUSE_RELEASE triggers
+ * @platform_stop_during_hw_free: Invoke the platform trigger during hw_free. This is needed for
+ *				  IPC4 where a pipeline is only paused during stop/pause/suspend
+ *				  triggers. The FW keeps the host DMA running in this case and
+ *				  therefore the host must do the same and should stop the DMA during
+ *				  hw_free.
  */
 struct sof_ipc_pcm_ops {
 	int (*hw_params)(struct snd_soc_component *component, struct snd_pcm_substream *substream,
@@ -123,6 +128,7 @@ struct sof_ipc_pcm_ops {
 				   struct snd_pcm_substream *substream);
 	bool reset_hw_params_during_stop;
 	bool ipc_first_on_start;
+	bool platform_stop_during_hw_free;
 };
 
 /**