diff options
| author | Stuart Longland <redhatter@gentoo.org> | 2010-06-18 12:56:10 +1000 |
|---|---|---|
| committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2010-06-19 02:33:44 +0100 |
| commit | 20630c7f5966419dd6a1f00b669a7771e228510a (patch) | |
| tree | 04e684f6720e9fece574570208d196da9c09574e | |
| parent | 43793207fdcede490edf26a813a92b11ef434a13 (diff) | |
ASoC: Fix overflow bug in SOC_DOUBLE_R_SX_TLV
When SX_TLV widgets are read, if the gain is set to a value below 0dB,
the mixer control is erroniously read as being at maximum volume.
The value read out of the CODEC register is never sign-extended, and
when the minimum value is subtracted (read; added, since the minimum is
negative) the result is a number greater than the maximum allowed value
for the control, and hence it saturates.
Solution: Mask the result so that it "wraps around", emulating
sign-extension.
Signed-off-by: Stuart Longland <redhatter@gentoo.org>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
| -rw-r--r-- | sound/soc/soc-core.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index 26f17323ef19..8b79d90efdc1 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -2396,8 +2396,8 @@ int snd_soc_get_volsw_2r_sx(struct snd_kcontrol *kcontrol, int val = snd_soc_read(codec, mc->reg) & mask; int valr = snd_soc_read(codec, mc->rreg) & mask; - ucontrol->value.integer.value[0] = ((val & 0xff)-min); - ucontrol->value.integer.value[1] = ((valr & 0xff)-min); + ucontrol->value.integer.value[0] = ((val & 0xff)-min) & mask; + ucontrol->value.integer.value[1] = ((valr & 0xff)-min) & mask; return 0; } EXPORT_SYMBOL_GPL(snd_soc_get_volsw_2r_sx); |