Re: Tool to configure sound

[Florian Kulzer <florian.kulzer+debian@icfo.es>]

On Thu, Nov 01, 2007 at 00:23:34 +0100, Richard Lyons wrote:
> On Wed, Oct 31, 2007 at 06:38:02PM +0100, Florian Kulzer wrote:
> 
> > On Wed, Oct 31, 2007 at 11:48:16 +0100, Richard Lyons wrote:
> [...]
> > OK, so the hardware works.
> >  
> > > Never mind -- I'll buy a phonograph, a soft cloth and scour the
> > > second-hand markets for vinyl...
> > 
> > To keep yourself entertained until you get the phonograph, you could
> > post the output of these commands:
> > 
> 
> $ cat /proc/asound/card0/codec* | head
> Codec: Realtek ALC883
> Address: 0
> Vendor Id: 0x10ec0883
> Subsystem Id: 0x1025160d
> Revision Id: 0x100002
> Default PCM: rates 0x560, bits 0x0e, types 0x1
> Default Amp-In caps: N/A
> Default Amp-Out caps: N/A
> Node 0x02 [Audio Output] wcaps 0x11: Stereo
>   PCM: rates 0x560, bits 0x0e, types 0x1
> 
> $ grep '.*' /sys/module/snd_hda_intel/parameters/*
> /sys/module/snd_hda_intel/parameters/enable:N
> /sys/module/snd_hda_intel/parameters/id:<NULL>
> /sys/module/snd_hda_intel/parameters/index:0
> /sys/module/snd_hda_intel/parameters/model:<NULL>
> /sys/module/snd_hda_intel/parameters/position_fix:0
> /sys/module/snd_hda_intel/parameters/probe_mask:-1
> /sys/module/snd_hda_intel/parameters/single_cmd:N
> 
> Maybe I'm dim or maybe it is just late, but I can't even guess what all
> that says.  I'm impressed you even knew to suggest those.  Do they help?

I am just following Documentation/sound/alsa/ALSA-Configuration.txt.
The "Documentation" directory is part of the kernel source; you can
also get it separately by installing the linux-doc-... package for your
version of the kernel. 

One source of problems with ALSA is that each driver (snd_hda_intel in
your case) has to support different codec chips (here: ALC883) and that
each codec chip can come in a number of different configurations
("models"). The ALSA developers are in an "arms race" with the laptop
manufacturers, trying to make sure that the driver recognizes the codec
chip model correctly for the ever-increasing number of laptop models. In
your case no specific codec chip model was declared when the module was
loaded, so the default configuration was chosen. This could mean that
there might be an additional volume control for your chip which is
currently inaccessible to you.

You can try different codec chip models (e.g. "3stack") by running:

modprobe -r snd_hda_intel
modprobe snd_hda_intel model=3stack

There might be a model which makes sound work right away, or which at
least gives you an additional control which you can unmute and turn up.
Maybe one of the other workarounds discussed in ALSA-Configuration.txt
will get you going. If you find module parameters that work then you can
append them to the hda-intel "options" line in /etc/modprobe.d/sound.

Other things to consider are:

- The problem might go away automatically if you upgrade to a newer
  version of ALSA and/or the kernel. (I don't recall if you mentioned
  which branch of Debian you are currently using.)

- Maybe you can avoid the trial-and-error if you find someone who
  figured it out already for your laptop model. (TuxMobil, etc.)

- The ALSA mailing list is the last resort if all else fails.

-- 
Regards,            | http://users.icfo.es/Florian.Kulzer
          Florian   |