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@gentoo.org
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@slimlogic.co.uk