ASoC: SOF: Intel: hda: reset dma_sata during suspend

When the stream is cleared during the suspend trigger,
the dma_data must be set to NULL and
snd_hdac_ext_stream_release() must be called to release
the link dev. Without this, some platforms run into
issues with triggering the host DMA during system resume.

Add the missing sequences to both hda_link_pcm_trigger() to
handle all streams that get suspended and to
hda_dsp_set_hw_params_upon_resume() to handle paused streams that
are reset during system suspend.

Also, because the dma_data is set to NULL during suspend,
add the checks to ensure link_dev is not NULL during
hw_params and hw_free to prevent NULL pointer dereferences.

BugLink: thesofproject/sof#4779
Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>

Author: ranj063

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

@@ -279,7 +279,7 @@ static int hda_link_pcm_prepare(struct snd_pcm_substream *substream,
 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 	int stream = substream->stream;
 
-	if (link_dev->link_prepared)
+	if (link_dev && link_dev->link_prepared)
 		return 0;
 
 	dev_dbg(sdev->dev, "hda: prepare stream dir %d\n", substream->stream);
@@ -306,6 +306,10 @@ static int hda_link_pcm_trigger(struct snd_pcm_substream *substream,
 	bus = hstream->bus;
 	rtd = asoc_substream_to_rtd(substream);
 
+	/* when paused streams are never released after system resume, link_dev would be NULL. */
+	if (!link_dev)
+		return 0;
+
 	link = snd_hdac_ext_bus_get_link(bus, asoc_rtd_to_codec(rtd, 0)->component->name);
 	if (!link)
 		return -EINVAL;
@@ -347,7 +351,10 @@ static int hda_link_pcm_trigger(struct snd_pcm_substream *substream,
 			snd_hdac_ext_link_clear_stream_id(link, stream_tag);
 		}
 
+		snd_soc_dai_set_dma_data(dai, substream, NULL);
+		snd_hdac_ext_stream_release(link_dev, HDAC_EXT_STREAM_TYPE_LINK);
 		link_dev->link_prepared = 0;
+		hda_stream->host_reserved = 0;
 
 		fallthrough;
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
@@ -377,11 +384,8 @@ static int hda_link_hw_free(struct snd_pcm_substream *substream,
 	rtd = asoc_substream_to_rtd(substream);
 	link_dev = snd_soc_dai_get_dma_data(dai, substream);
 
-	if (!link_dev) {
-		dev_dbg(dai->dev,
-			"%s: link_dev is not assigned\n", __func__);
-		return -EINVAL;
-	}
+	if (!link_dev)
+		return 0;
 
 	hda_stream = hstream_to_sof_hda_stream(link_dev);
 

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

@@ -922,16 +922,21 @@ int hda_dsp_set_hw_params_upon_resume(struct snd_sof_dev *sdev)
 		 * explicitly during suspend.
 		 */
 		if (stream->link_substream) {
+			struct snd_soc_dai *cpu_dai;
+
 			rtd = asoc_substream_to_rtd(stream->link_substream);
+			cpu_dai = asoc_rtd_to_cpu(rtd, 0);
 			name = asoc_rtd_to_codec(rtd, 0)->component->name;
 			link = snd_hdac_ext_bus_get_link(bus, name);
 			if (!link)
 				return -EINVAL;
 
-			stream->link_prepared = 0;
+			snd_soc_dai_set_dma_data(cpu_dai, stream->link_substream, NULL);
+			snd_hdac_ext_stream_release(link_dev, HDAC_EXT_STREAM_TYPE_LINK);
+			link_dev->link_prepared = 0;
+			hda_stream->host_reserved = 0;
 
-			if (hdac_stream(stream)->direction ==
-				SNDRV_PCM_STREAM_CAPTURE)
+			if (hdac_stream(stream)->direction == SNDRV_PCM_STREAM_CAPTURE)
 				continue;
 
 			stream_tag = hdac_stream(stream)->stream_tag;