linux-kernel - [PATCH 6/9] ASoC: codecs: wm8955: Fix register cache incoherency

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Message-Id: <1293568684-9626-7-git-send-email-lars@metafoo.de>
Date:	Tue, 28 Dec 2010 21:38:00 +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>,
	Ian Lartey <ian@...nsource.wolfsonmicro.com>,
	Dimitris Papastamos <dp@...nsource.wolfsonmicro.com>
Subject: [PATCH 6/9] ASoC: codecs: wm8955: Fix register cache incoherency

The multi-component patch(commit f0fba2ad1) moved the allocation of the
register cache from the driver to the ASoC core. Most drivers where adjusted to
this, but the wm8955 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 can lead to
undefined behaviour.
This patch fixes the issue by changing the wm8955 driver to use the
generic register cache in its private functions.

Signed-off-by: Lars-Peter Clausen <lars@...afoo.de>
Cc: Ian Lartey <ian@...nsource.wolfsonmicro.com>
Cc: Dimitris Papastamos <dp@...nsource.wolfsonmicro.com>

---
Compile tested only
---
 sound/soc/codecs/wm8955.c |   30 +++++++++++++++---------------
 1 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/sound/soc/codecs/wm8955.c b/sound/soc/codecs/wm8955.c
index 9cbab8e..fdc7c8a 100644
--- a/sound/soc/codecs/wm8955.c
+++ b/sound/soc/codecs/wm8955.c
@@ -42,8 +42,6 @@ static const char *wm8955_supply_names[WM8955_NUM_SUPPLIES] = {
 struct wm8955_priv {
 	enum snd_soc_control_type control_type;
 
-	u16 reg_cache[WM8955_MAX_REGISTER + 1];
-
 	unsigned int mclk_rate;
 
 	int deemph;
@@ -768,6 +766,7 @@ static int wm8955_set_bias_level(struct snd_soc_codec *codec,
 				 enum snd_soc_bias_level level)
 {
 	struct wm8955_priv *wm8955 = snd_soc_codec_get_drvdata(codec);
+	u16 *reg_cache = codec->reg_cache;
 	int ret, i;
 
 	switch (level) {
@@ -800,14 +799,14 @@ static int wm8955_set_bias_level(struct snd_soc_codec *codec,
 			/* Sync back cached values if they're
 			 * different from the hardware default.
 			 */
-			for (i = 0; i < ARRAY_SIZE(wm8955->reg_cache); i++) {
+			for (i = 0; i < codec->driver->reg_cache_size; i++) {
 				if (i == WM8955_RESET)
 					continue;
 
-				if (wm8955->reg_cache[i] == wm8955_reg[i])
+				if (reg_cache[i] == wm8955_reg[i])
 					continue;
 
-				snd_soc_write(codec, i, wm8955->reg_cache[i]);
+				snd_soc_write(codec, i, reg_cache[i]);
 			}
 
 			/* Enable VREF and VMID */
@@ -902,6 +901,7 @@ static int wm8955_probe(struct snd_soc_codec *codec)
 {
 	struct wm8955_priv *wm8955 = snd_soc_codec_get_drvdata(codec);
 	struct wm8955_pdata *pdata = dev_get_platdata(codec->dev);
+	u16 *reg_cache = codec->reg_cache;
 	int ret, i;
 
 	ret = snd_soc_codec_set_cache_io(codec, 7, 9, wm8955->control_type);
@@ -934,25 +934,25 @@ static int wm8955_probe(struct snd_soc_codec *codec)
 	}
 
 	/* Change some default settings - latch VU and enable ZC */
-	wm8955->reg_cache[WM8955_LEFT_DAC_VOLUME] |= WM8955_LDVU;
-	wm8955->reg_cache[WM8955_RIGHT_DAC_VOLUME] |= WM8955_RDVU;
-	wm8955->reg_cache[WM8955_LOUT1_VOLUME] |= WM8955_LO1VU | WM8955_LO1ZC;
-	wm8955->reg_cache[WM8955_ROUT1_VOLUME] |= WM8955_RO1VU | WM8955_RO1ZC;
-	wm8955->reg_cache[WM8955_LOUT2_VOLUME] |= WM8955_LO2VU | WM8955_LO2ZC;
-	wm8955->reg_cache[WM8955_ROUT2_VOLUME] |= WM8955_RO2VU | WM8955_RO2ZC;
-	wm8955->reg_cache[WM8955_MONOOUT_VOLUME] |= WM8955_MOZC;
+	reg_cache[WM8955_LEFT_DAC_VOLUME] |= WM8955_LDVU;
+	reg_cache[WM8955_RIGHT_DAC_VOLUME] |= WM8955_RDVU;
+	reg_cache[WM8955_LOUT1_VOLUME] |= WM8955_LO1VU | WM8955_LO1ZC;
+	reg_cache[WM8955_ROUT1_VOLUME] |= WM8955_RO1VU | WM8955_RO1ZC;
+	reg_cache[WM8955_LOUT2_VOLUME] |= WM8955_LO2VU | WM8955_LO2ZC;
+	reg_cache[WM8955_ROUT2_VOLUME] |= WM8955_RO2VU | WM8955_RO2ZC;
+	reg_cache[WM8955_MONOOUT_VOLUME] |= WM8955_MOZC;
 
 	/* Also enable adaptive bass boost by default */
-	wm8955->reg_cache[WM8955_BASS_CONTROL] |= WM8955_BB;
+	reg_cache[WM8955_BASS_CONTROL] |= WM8955_BB;
 
 	/* Set platform data values */
 	if (pdata) {
 		if (pdata->out2_speaker)
-			wm8955->reg_cache[WM8955_ADDITIONAL_CONTROL_2]
+			reg_cache[WM8955_ADDITIONAL_CONTROL_2]
 				|= WM8955_ROUT2INV;
 
 		if (pdata->monoin_diff)
-			wm8955->reg_cache[WM8955_MONO_OUT_MIX_1]
+			reg_cache[WM8955_MONO_OUT_MIX_1]
 				|= WM8955_DMEN;
 	}
 
-- 
1.7.2.3

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