On Fri, 2010-06-18 at 12:56 +1000, Stuart Longland wrote: > 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@xxxxxxxxxx> > --- > 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 a82a797..0470288 100644 > --- a/sound/soc/soc-core.c > +++ b/sound/soc/soc-core.c > @@ -2400,8 +2400,8 @@ 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); Acked-by: Liam Girdwood <lrg@xxxxxxxxxxxxxxx> -- Freelance Developer, SlimLogic Ltd ASoC and Voltage Regulator Maintainer. http://www.slimlogic.co.uk _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
