[alsa-devel] Avoid overload of PCM volume on Cx5045 codec

[Takashi Iwai]

At Thu, 19 Jun 2008 13:34:25 +0200,
=?ISO-8859-1?Q?Andreas_P=E5hlsson?= wrote:
> 
> Hardware:
> 
>     description: Notebook
>     product: AMILO Pro V3205
>     vendor: FUJITSU SIEMENS
>     version: Rev 1
>     serial: YK2H004201
>     width: 32 bits
>     capabilities: smbios-2.4 dmi-2.4 smp-1.4 smp
>     configuration: boot=oem-specific chassis=notebook cpus=2
> uuid=00CAAE3D-9113-0E10-AFC7-E4C0949DBF47
> 
> 
> alsa-info.sh:
> 
> http://pastebin.ca/1050962

Thanks.

> I have of course played with all the settings with alsamixer before
> compiling a kernelmodule. As per the comment to the patch the sound
> can become very distorted without it. 6 dB works fine for me.

Hm, but it has far higher values.  Do they also work fine (suppose you
reverted the amp override patch)?

> For me it is a little strange that it is the PCM volume and not the
> Master volume that can be boosted. PCM sounds like it would be a
> internal digital amplification control, Master sounds more like an
> analog output amplifier control. But thats just me and I don't know
> the chip at all.

It's just a matter of name.  In general, "PCM" volume means that the
volume control path specific to the PCM, not for other sources.  In
the case of Conexant codec, there is no loopback route, so it doesn't
matter, though.


Takashi

> 
> regards,
> 
> Andreas
> 
> 2008/6/19 Takashi Iwai <tiwai at suse.de>:
> > At Wed, 18 Jun 2008 21:58:40 +0200,
> > =?ISO-8859-1?Q?Andreas_P=E5hlsson?= wrote:
> >>
> >> Hello.
> >>
> >> I've had a problem with low volume on my laptop and while scratching
> >> this itch I found the patch titled "hda-codec - Avoid overload of PCM
> >> volume on Cx5045 codec" I reverted this patch and of course got a lot
> >> more volume. The description states: "The PCM volume of Cx5045 codec
> >> has overload that isn't useful but rather harmful.  Add a hack to
> >> override the amp info to set the max level 0 dB.". Does anybody know
> >> where to find more information on a better default value for the max
> >> level setting?
> >
> > Then maybe this workaround is specific to HP laptops.
> > Could you give the alsa-info.sh output, and a more detailed
> > information of your laptop (vendor, model)?  Before working on the
> > source code, one should check the mixer setting at first.
> >
> >
> > Takashi
> > _______________________________________________
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> > Alsa-devel at alsa-project.org
> > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
> >
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