linux-kernel - [PATCH 2/9] ASoC: codecs: max98088: Fix register cache incoherency

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Date:	Fri, 24 Dec 2010 14:47:57 +0100
From:	Lars-Peter Clausen <lars@...afoo.de>
To:	Mark Brown <broonie@...nsource.wolfsonmicro.com>,
	Liam Girdwood <lrg@...mlogic.co.uk>
Cc:	alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
	Lars-Peter Clausen <lars@...afoo.de>,
	Peter Hsiang <Peter.Hsiang@...im-ic.com>
Subject: [PATCH 2/9] ASoC: codecs: max98088: Fix register cache incoherency

The multi-component patch(commit f0fba2ad1) introduced a generic register cache
framework. But the wm8753 driver still uses its own register cache for its
private functions, while functions from the ASoC core use the generic cache.
Thus we end up with two from each other incoherent caches, which leads to undefined
behaviour.
This pachtes fixes the issue by changing the max98088 driver to use the generic
cache framework.

Signed-off-by: Lars-Peter Clausen <lars@...afoo.de>
Cc: Peter Hsiang <Peter.Hsiang@...im-ic.com>

---
Compile tested only
---
 sound/soc/codecs/max98088.c |   13 +++++++------
 1 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/sound/soc/codecs/max98088.c b/sound/soc/codecs/max98088.c
index 335a002..c7e57fb 100644
--- a/sound/soc/codecs/max98088.c
+++ b/sound/soc/codecs/max98088.c
@@ -39,7 +39,6 @@ struct max98088_cdata {
 };
 
 struct max98088_priv {
-       u8 reg_cache[M98088_REG_CNT];
        enum max98088_type devtype;
        void *control_data;
        struct max98088_pdata *pdata;
@@ -1589,7 +1588,7 @@ static int max98088_dai2_set_fmt(struct snd_soc_dai *codec_dai,
 
 static void max98088_sync_cache(struct snd_soc_codec *codec)
 {
-       struct max98088_priv *max98088 = snd_soc_codec_get_drvdata(codec);
+       unsigned int val;
        int i;
 
        if (!codec->cache_sync)
@@ -1600,14 +1599,17 @@ static void max98088_sync_cache(struct snd_soc_codec *codec)
        /* write back cached values if they're writeable and
         * different from the hardware default.
         */
-       for (i = 1; i < ARRAY_SIZE(max98088->reg_cache); i++) {
+       for (i = 1; i < codec->driver->reg_cache_size; i++) {
                if (!max98088_access[i].writable)
                        continue;
 
-               if (max98088->reg_cache[i] == max98088_reg[i])
+               if (snd_soc_cache_read(codec, i, &val))
+                       continue;
+
+               if (val == max98088_reg[i])
                        continue;
 
-               snd_soc_write(codec, i, max98088->reg_cache[i]);
+               snd_soc_write(codec, i, val);
        }
 
        codec->cache_sync = 0;
@@ -1952,7 +1954,6 @@ static int max98088_probe(struct snd_soc_codec *codec)
        int ret = 0;
 
        codec->cache_sync = 1;
-       memcpy(codec->reg_cache, max98088_reg, sizeof(max98088_reg));
 
        ret = snd_soc_codec_set_cache_io(codec, 8, 8, SND_SOC_I2C);
        if (ret != 0) {
-- 
1.7.2.3

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