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Re: Questions about sis7012+snd_intel8x0 sound card problem



On Sunday 10 July 2005 13:01, Trace Green wrote:
> Hi, all
>
> My sound card is SiS7012 integrated, vendor and
> device id is 1039:7012. I tried to use alsaconf to
> config my sound card, it loads snd_intel8x0.
>
> But i cann't hear any sound, when i use alsamixer to
> check, i find pcm and master channel is just 0, i
> can't change the value of them. of course, it is not
> muted.
>
> This seems an old problem, i tried to find the answer
> in google, fail....
>
> Anyideas?

amixer (the mixer problem for ALSA) should "just 
work" (TM)

But if it's not, I do have a few ideas.

It's possible you are successfully setting the volume of 
some part of the card, but not of the part of your card 
you think you are. Some cards driven by the 
snd-intel8x0 driver have a "quirk" which means that the 
surround volume control and the master volume control 
(if you have surround sound) or the headphone volume 
and the master volume control, are swapped. I'm not 
totally sure of the details but my reading of the 
documentation suggests the _pins are wired into the 
board the wrong way round (!!!!)_ on some boards... The 
driver claims to be able to detect this in some cases 
and compensate for it -- but my board, which is 
different to yours, is an example of one it doesn't.

Try using amixer to unmute and set the volume of your 
card (you may possibly have to be root to do this, I 
don't on my machine but I'm not sure if that's 
universal).

amixer set Headphone 50 unmute

This will unmute the Headphone setting and 
simultaneously set the volume to 50 (either 50 on a 
scale of 1 to something or 50%, not sure what controls 
which it does, either way 50 should be audible).

If you don't have amixer on your machine, apt-get 
alsa-utils first then you will.

Then you can use aplay <sound file> to check your sound 
is working. amixer set Master 50 should also set master 
volume, amixer set pcm 100 to set PCM to 100% (then 
control actual volume with either Master or Headphone 
setting)

One caveat -- I'm not sure if the settings are 
driver-dependent or card-dependent. My money is on 
driver-dependent but I've been wrong before (back in 
2002 sometime I think... just kidding). Anyway, 
amixer's "set" commands are CASE SENSITIVE so first do:

amixer | grep 'Simple mixer'

and that'll give you a list of mixer settings you can 
change. Then be sure to use the setting EXACTLY AS IT 
APPEARS. For example my master volume is 'Master' so I 
can change my volume with:

amixer set Master 50

for example. Actually I use amixer set Headphone 50 
since my card has the Headphone / Master Swapped 
problem and I haven't fixed it yet.

Headphone will probably be muted unless you've unmuted 
it. Actually, on my board ALL the settings using ALSA 
were muted until I unmuted them -- even though I'd been 
successfully playing sounds using OSS under a 2.4 
kernel until I upgraded to 2.6 and ALSA.

Summary:

Make sure you are using amixer
Make sure you really have unmuted the mixer settings -- 
it says off if muted and on if not.
use amixer set <Master|Headphone|pcm> <number> <mute|
unmute> to change settings
Test with aplay
Consider the possibility that your Headphone and Master 
settings are swapped if none of the above solves your 
problem.

The driver claims it can be forced to swap settings so 
Master does what it says it does using module options, 
but I haven't got that working yet.

(Info about the "quirk" involving master / headphone 
swap came from <kernel source 
dir>/Documentation/sound/ALSA Configuration.txt -- 
search that file for the word intel.

Mark



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