[PATCH] ASoC: WM9712 Codec: Workaround an unmute problem

[John Bonesio]

When setting the PCM mixer (unuting), the main Headphone mixer setting gets
set back to mute. At this time it appears this is occuring in hardware.

Signed-off-by: John Bonesio <bones at secretlab.ca>
---
 sound/soc/codecs/wm9712.c |   21 +++++++++++++++++++--
 1 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/sound/soc/codecs/wm9712.c b/sound/soc/codecs/wm9712.c
index b57c817..6f8d164 100644
--- a/sound/soc/codecs/wm9712.c
+++ b/sound/soc/codecs/wm9712.c
@@ -28,6 +28,7 @@ static unsigned int ac97_read(struct snd_soc_codec *codec,
 	unsigned int reg);
 static int ac97_write(struct snd_soc_codec *codec,
 	unsigned int reg, unsigned int val);
+static int ac97_flush(struct snd_soc_codec *codec, unsigned int reg);
 
 /*
  * WM9712 register cache
@@ -177,9 +178,14 @@ static int mixer_event(struct snd_soc_dapm_widget *w,
 	else
 		ac97_write(w->codec, AC97_VIDEO, mic | 0x8000);
 
-	if (l & 0x2 || r & 0x2)
+	if (l & 0x2 || r & 0x2) {
 		ac97_write(w->codec, AC97_PCM, pcm & 0x7fff);
-	else
+		/*
+		 * Workaround an apparent bug where the headphone mute setting
+		 * is modified when the PCM mute setting is enabled.
+		 */
+		ac97_flush(w->codec, AC97_HEADPHONE);
+	} else
 		ac97_write(w->codec, AC97_PCM, pcm | 0x8000);
 
 	if (l & 0x4 || r & 0x4)
@@ -472,6 +478,17 @@ static int ac97_write(struct snd_soc_codec *codec, unsigned int reg,
 	return 0;
 }
 
+static int ac97_flush(struct snd_soc_codec *codec, unsigned int reg)
+{
+	unsigned int val;
+	u16 *cache = codec->reg_cache;
+
+	if ((reg >> 1) < (ARRAY_SIZE(wm9712_reg))) {
+		val = cache[reg >> 1];
+		soc_ac97_ops.write(codec->ac97, reg, val);
+	}
+}
+
 static int ac97_prepare(struct snd_pcm_substream *substream,
 			struct snd_soc_dai *dai)
 {
-- 
1.6.0.4


--=-3OuCfmlE7wntN9J+RSz+--