From 20630c7f5966419dd6a1f00b669a7771e228510a Mon Sep 17 00:00:00 2001 From: Stuart Longland <redhatter@gentoo.org> Date: Fri, 18 Jun 2010 12:56:10 +1000 Subject: [PATCH] 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> --- sound/soc/soc-core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index 26f17323ef19d..8b79d90efdc12 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); -- 2.30.2