[alsa-devel] Constant noise on HDA ALC275

[Takashi Iwai]

At Fri, 02 Nov 2012 12:29:40 +0100,
Julien Danjou wrote:
> 
> On Fri, Nov 02 2012, Takashi Iwai wrote:
> 
> >> I just did that using the hda-analyzer tool. I changed 0x14 to uses 0x0c
> >> as a source, and it's indeed much better. The noise disappear when
> >> neither master or speaker is muted, and actually the music playback
> >> sounds better and without the little background noise I still hear on
> >> low volume level.
> >
> > Good to hear.  What's the remaining issue?
> 
> Well, it's still not perfect, and as I wrote, if any of "master" or
> "speaker" is muted, the noise kicks back in instantly. :(

OK, the behavior wasn't clear in your text above, so I asked it again.
(mute and unmute are pretty confusing :)

> > The current parser prefers the line-out as the primary output over the
> > headphone.  Then it tries to assign from the smaller NID, so 0x0c is
> > assigned to the line-out (which is the speaker in your case), then
> > 0x0d is to the headphone.
> 
> Ok, thanks for the explanation.
> 
> >> I'm still trying to find a way to fix the noise when speaker or master
> >> are muted. No chance so far. :(
> >
> > Do you mean that the noise is there with rerouting like the above, or
> > you are asking for a patch to achieve the rerouting?
> 
> If "master" or "speaker" is muted, the noise kicks back in, whatever the
> routing is.
> 
> 
> At this point, I wonder if it wouldn't be simpler to just boot the
> machine under Windows and dump the HDA state to see how the Windows
> driver set up all the routing. Do you think this kind of approach would
> work, and in that case, is there a tool do achieve that?

I have no idea about Windows, sorry.


Takashi