[alsa-devel] Grey noise with HDA Intel PCH

[Julian Wollrath]

> > > > Simple mixer control 'Mic',0
> > > >   Front Left: Playback 0 [0%] [-34.50dB] [on]
> > > >   Front Right: Playback 0 [0%] [-34.50dB] [on]
> > > 
> > > This plays any noise from the mic input.
> > Turning it off makes no difference since capture is turned off
> > anyway:
> 
> This is a loopback mixer element, it has nothing to do with capture
> stream.
> 
> The likely culprit of the static noises is the signal from the analog
> loopback.  In some cases, you can disable the whole loopback via
> "Loopback Mixing" mixer element on the fly.  In some cases, you'd need
> to disable each mixer input (e.g. "Mic Playback Switch").
> In some cases (e.g. on some Sony and Dell laptops), you'd need to
> disable the complete analog loopback at the initialization.
> 
> The last one can be done via the early patching or sysfs
> reconfiguration, pass "mixer_nid = 0" hint.  See HD-Audio.txt for a
> brief instruction.
Sadly, that did not help.


Cheers,
Julian