[alsa-devel] [PATCH][topic/symmetry] ASoC: soc-pcm: move DAIs parameters cleaning into hw_free()

[Nicolin Chen]

We're now applying soc_hw_params_symmetry() to reject unmatched parameters
while we clear parameters in soc_pcm_close(). So here's a use case might be
broken by this mechanism: aplay -Dhw:0 44100.wav 48000.wav 32000.wav

In this case, we call soc_pcm_open()->soc_pcm_hw_params()->soc_pcm_hw_free()
->soc_pcm_hw_params()->soc_pcm_hw_free()->soc_pcm_close() in order. As we
only clear parameters in soc_pcm_close(). The parameters would be remained
in the system even if the playback of 44100.wav is finished.

Thus, this patch is trying to move parameters cleaning into hw_free() so that
the system can continue to serve this kind of use case.

Also, since we set them in hw_params(), it should be better to clear them in
hw_free() for symmetry.

Signed-off-by: Nicolin Chen <b42378 at freescale.com>
---
 sound/soc/soc-pcm.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index 60d9cfb..d519757 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -443,19 +443,6 @@ static int soc_pcm_close(struct snd_pcm_substream *substream)
 	codec_dai->active--;
 	codec->active--;
 
-	/* clear the corresponding DAIs rate when inactive */
-	if (!cpu_dai->active) {
-		cpu_dai->rate = 0;
-		cpu_dai->channels = 0;
-		cpu_dai->sample_bits = 0;
-	}
-
-	if (!codec_dai->active) {
-		codec_dai->rate = 0;
-		codec_dai->channels = 0;
-		codec_dai->sample_bits = 0;
-	}
-
 	/* Muting the DAC suppresses artifacts caused during digital
 	 * shutdown, for example from stopping clocks.
 	 */
@@ -671,6 +658,19 @@ static int soc_pcm_hw_free(struct snd_pcm_substream *substream)
 
 	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
 
+	/* clear the corresponding DAIs parameters when going to be inactive */
+	if (cpu_dai->active == 1) {
+		cpu_dai->rate = 0;
+		cpu_dai->channels = 0;
+		cpu_dai->sample_bits = 0;
+	}
+
+	if (codec_dai->active == 1) {
+		codec_dai->rate = 0;
+		codec_dai->channels = 0;
+		codec_dai->sample_bits = 0;
+	}
+
 	/* apply codec digital mute */
 	if (!codec->active)
 		snd_soc_dai_digital_mute(codec_dai, 1, substream->stream);
-- 
1.8.4