From: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>

When a PCM is restarted after a snd_pcm_drain/snd_pcm_drop(), the prepare
callback will be invoked and the hw_params will be set again. For the
HDA DAI's, the hw_params function handles this case already but not for
the non-HDA DAI's. So, add the check for link_prepared to verify if the
hw_params should be done again or not. Additionally, for SDW DAI's reset
the PCMSyCM registers as would be done in the case of a start after a
hw_free.

Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 sound/soc/sof/intel/hda-dai.c | 36 +++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/sound/soc/sof/intel/hda-dai.c b/sound/soc/sof/intel/hda-dai.c
index 1c823f9eea57..8cccf38967e7 100644
--- a/sound/soc/sof/intel/hda-dai.c
+++ b/sound/soc/sof/intel/hda-dai.c
@@ -370,6 +370,13 @@ static int non_hda_dai_hw_params_data(struct snd_pcm_substream *substream,
 		return -EINVAL;
 	}
 
+	sdev = widget_to_sdev(w);
+	hext_stream = ops->get_hext_stream(sdev, cpu_dai, substream);
+
+	/* nothing more to do if the link is already prepared */
+	if (hext_stream && hext_stream->link_prepared)
+		return 0;
+
 	/* use HDaudio stream handling */
 	ret = hda_dai_hw_params_data(substream, params, cpu_dai, data, flags);
 	if (ret < 0) {
@@ -377,7 +384,6 @@ static int non_hda_dai_hw_params_data(struct snd_pcm_substream *substream,
 		return ret;
 	}
 
-	sdev = widget_to_sdev(w);
 	if (sdev->dspless_mode_selected)
 		return 0;
 
@@ -482,6 +488,31 @@ int sdw_hda_dai_hw_params(struct snd_pcm_substream *substream,
 	int ret;
 	int i;
 
+	ops = hda_dai_get_ops(substream, cpu_dai);
+	if (!ops) {
+		dev_err(cpu_dai->dev, "DAI widget ops not set\n");
+		return -EINVAL;
+	}
+
+	sdev = widget_to_sdev(w);
+	hext_stream = ops->get_hext_stream(sdev, cpu_dai, substream);
+
+	/* nothing more to do if the link is already prepared */
+	if (hext_stream && hext_stream->link_prepared)
+		return 0;
+
+	/*
+	 * reset the PCMSyCM registers to handle a prepare callback when the PCM is restarted
+	 * due to xruns or after a call to snd_pcm_drain/drop()
+	 */
+	ret = hdac_bus_eml_sdw_map_stream_ch(sof_to_bus(sdev), link_id, cpu_dai->id,
+					     0, 0, substream->stream);
+	if (ret < 0) {
+		dev_err(cpu_dai->dev, "%s:  hdac_bus_eml_sdw_map_stream_ch failed %d\n",
+			__func__, ret);
+		return ret;
+	}
+
 	data.dai_index = (link_id << 8) | cpu_dai->id;
 	data.dai_node_id = intel_alh_id;
 	ret = non_hda_dai_hw_params_data(substream, params, cpu_dai, &data, flags);
@@ -490,10 +521,7 @@ int sdw_hda_dai_hw_params(struct snd_pcm_substream *substream,
 		return ret;
 	}
 
-	ops = hda_dai_get_ops(substream, cpu_dai);
-	sdev = widget_to_sdev(w);
 	hext_stream = ops->get_hext_stream(sdev, cpu_dai, substream);
-
 	if (!hext_stream)
 		return -ENODEV;
 
-- 
2.43.0