ASoC: SOF: Intel: hda-dai: reset dma_data and release stream

The sequences are missing a call to snd_soc_dai_set_dma_data() when
the stream is cleared, as well as a release of the stream, and tests
to avoid pointer dereferences.

This fixes an underflow issue in a corner case with two streams paused
before a suspend-resume cycle. After resume, the pause_release of the
last stream causes an underflow due to an invalid sequence.

This problem probably existed since the beginning and is only see with
prototypes of a 'deep-buffer' capability, which depends on additional
ASoC fixes, so there's is no Fixes: tag and no real requirement to
backport this patch.

BugLink: thesofproject#3151
Co-developed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

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

@@ -208,7 +208,7 @@ static int hda_dai_link_prepare(struct snd_pcm_substream *substream)
 	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(cpu_dai->component);
 	int stream = substream->stream;
 
-	if (he_stream->link_prepared)
+	if (he_stream && he_stream->link_prepared)
 		return 0;
 
 	dev_dbg(sdev->dev, "%s: prepare stream dir %d\n", __func__, substream->stream);
@@ -232,6 +232,9 @@ static int hda_dai_link_trigger(struct snd_pcm_substream *substream, int cmd)
 		return -EINVAL;
 
 	dev_dbg(cpu_dai->dev, "%s: cmd=%d\n", __func__, cmd);
+	if (!he_stream)
+		return 0;
+
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
@@ -243,7 +246,8 @@ static int hda_dai_link_trigger(struct snd_pcm_substream *substream, int cmd)
 			stream_tag = hdac_stream(he_stream)->stream_tag;
 			snd_hdac_ext_link_clear_stream_id(link, stream_tag);
 		}
-
+		snd_soc_dai_set_dma_data(cpu_dai, substream, NULL);
+		snd_hdac_ext_stream_release(he_stream, HDAC_EXT_STREAM_TYPE_LINK);
 		he_stream->link_prepared = 0;
 
 		fallthrough;
@@ -466,6 +470,8 @@ static int hda_dai_suspend(struct hdac_bus *bus)
 
 	/* set internal flag for BE */
 	list_for_each_entry(s, &bus->stream_list, list) {
+		struct sof_intel_hda_stream *hda_stream;
+
 		he_stream = stream_to_hdac_ext_stream(s);
 
 		if (!he_stream)
@@ -493,7 +499,8 @@ static int hda_dai_suspend(struct hdac_bus *bus)
 				stream_tag = hdac_stream(he_stream)->stream_tag;
 				snd_hdac_ext_link_clear_stream_id(link, stream_tag);
 			}
-
+			snd_soc_dai_set_dma_data(cpu_dai, he_stream->link_substream, NULL);
+			snd_hdac_ext_stream_release(he_stream, HDAC_EXT_STREAM_TYPE_LINK);
 			he_stream->link_prepared = 0;
 
 			/*
@@ -507,6 +514,10 @@ static int hda_dai_suspend(struct hdac_bus *bus)
 			if (ret < 0)
 				return ret;
 		}
+
+		/* free the host DMA channel reserved by hostless streams */
+		hda_stream = hstream_to_sof_hda_stream(he_stream);
+		hda_stream->host_reserved = 0;
 	}
 
 	return 0;