[alsa-devel] [2.6.29-rc3][PATCH 1/2] ASoC: TLV320AIC3X: Fix kcontrol's private value use in put callback

[Jarkko Nikula]

From: Eero Nurkkala <ext-eero.nurkkala at nokia.com>

Function snd_soc_dapm_put_volsw_aic3x misuses the kcontrol's private value
by still accessing it as bitfields even SOC_SINGLE_VALUE constructs it
as a pointer into struct soc_mixer_control after the commit
4eaa9819dc08d7bfd1065ce530e31b18a119dcaf.

This was causing arbitrary register writes when touching the controls
defined with SOC_DAPM_SINGLE_AIC3X.

Signed-off-by: Eero Nurkkala <ext-eero.nurkkala at nokia.com>
Acked-by: Jarkko Nikula <jarkko.nikula at nokia.com>
---
 sound/soc/codecs/tlv320aic3x.c |   11 +++++++----
 1 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/sound/soc/codecs/tlv320aic3x.c b/sound/soc/codecs/tlv320aic3x.c
index b47a749..aea0cb7 100644
--- a/sound/soc/codecs/tlv320aic3x.c
+++ b/sound/soc/codecs/tlv320aic3x.c
@@ -165,10 +165,13 @@ static int snd_soc_dapm_put_volsw_aic3x(struct snd_kcontrol *kcontrol,
 					struct snd_ctl_elem_value *ucontrol)
 {
 	struct snd_soc_dapm_widget *widget = snd_kcontrol_chip(kcontrol);
-	int reg = kcontrol->private_value & 0xff;
-	int shift = (kcontrol->private_value >> 8) & 0x0f;
-	int mask = (kcontrol->private_value >> 16) & 0xff;
-	int invert = (kcontrol->private_value >> 24) & 0x01;
+	struct soc_mixer_control *mc =
+		(struct soc_mixer_control *)kcontrol->private_value;
+	unsigned int reg = mc->reg;
+	unsigned int shift = mc->shift;
+	int max = mc->max;
+	unsigned int mask = (1 << fls(max)) - 1;
+	unsigned int invert = mc->invert;
 	unsigned short val, val_mask;
 	int ret;
 	struct snd_soc_dapm_path *path;
-- 
1.5.6.5