[alsa-devel] [PATCH 1/3] ASoC: cs4270: fix Master Capture Switch polarity

Mark Brown broonie at sirena.org.uk
Sun Apr 26 11:49:17 CEST 2009

On Fri, Apr 24, 2009 at 10:45:29AM -0500, Timur Tabi wrote:
> Daniel Mack wrote:
> > The control modifies the MUTE register, hence the polarity must be
> > inverted.

>                             L    R
>                             CAPTUR
>                           < Master >

> What exactly does this mean?  Which one is supposed to mean "muted"?

Capture is enabled in the picture above; often when the alsamixer UI is
confusing amixer is a bit clearer about what's going on.

> And how come even though this switch is a SOC_DOUBLE, I cannot control
> the left and right channel independently with the < and > keys, and the
> "M" key doesn't toggle it either.

This is a property of capture controls.  I'm not entirely sure why,
CCing in Takashi who should be able to offer more knowledgable comment.

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