[PATCH v2 1/2] ASoC: intel: atom: Add period size constraint

[Brent Lu <brent.lu@intel.com>]

Use constraint to enforce the period sizes which are validated in
Android BSP.

Signed-off-by: Brent Lu <brent.lu@intel.com>
---
 sound/soc/intel/atom/sst-mfld-platform-pcm.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/sound/soc/intel/atom/sst-mfld-platform-pcm.c b/sound/soc/intel/atom/sst-mfld-platform-pcm.c
index 49b9f18..70100ef 100644
--- a/sound/soc/intel/atom/sst-mfld-platform-pcm.c
+++ b/sound/soc/intel/atom/sst-mfld-platform-pcm.c
@@ -300,6 +300,16 @@ static void power_down_sst(struct sst_runtime_stream *stream)
 	stream->ops->power(sst->dev, false);
 }
 
+static const unsigned int media_period_size[] = {
+	/* sizes validated on Android platform */
+	240, 320, 960, 3072,
+};
+
+static const struct snd_pcm_hw_constraint_list constraints_media_period_size = {
+	.count = ARRAY_SIZE(media_period_size),
+	.list  = media_period_size,
+};
+
 static int sst_media_open(struct snd_pcm_substream *substream,
 		struct snd_soc_dai *dai)
 {
@@ -333,6 +343,11 @@ static int sst_media_open(struct snd_pcm_substream *substream,
 	if (ret_val < 0)
 		return ret_val;
 
+	/* Avoid using period size which is not validated */
+	snd_pcm_hw_constraint_list(substream->runtime, 0,
+			SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
+			&constraints_media_period_size);
+
 	/* Make sure, that the period size is always even */
 	snd_pcm_hw_constraint_step(substream->runtime, 0,
 			   SNDRV_PCM_HW_PARAM_PERIODS, 2);
-- 
2.7.4