Re: no sound with 2.6.5 kernel - RESOLVED
On April 16, 2004 09:30 pm, Slaven Peles wrote:
>
> Some people have reported that upgrade to 2.6.5 solved their sound
> problems, but in my case 2.6.5 "turned" sound off. I am running sid with
> debian precompiled kernel (2.6.5-1-686), I use alsa, and I have Intel's
> onboard sound card:
>
> 0000:00:1f.5 Multimedia audio controller: Intel Corp. 82801DB (ICH4) AC'97
> Audio Controller (rev 03)
>
> If I boot kernel 2.6.4 or 2.4.24 with precompiled alsa modules, sound works
> fine. For each kernel all modules load properly. Is there some
> configuration option that I should change in order to enable sound with
> 2.6.5 kernel or I should just file a bug?
>
Hi,
Takashi Iwai, alsa developer in charge, helped me figure out what the problem
above was. As of version 1.0.4 'External Amplifier' configuration option for
alsa mixer was changed, so the upgrade to kernel 2.6.5, left the sound
misconfigured. Here is Takashi's explanation:
>most likely the mixer configuration was screwed up after the update
> because of this change of mixer element. as written above, it was
> named formerly 'External Amplifier Power Down', and should be OFF to
> power up the amp. since it's quite confusing, now it becamse
> 'External Amplifier', and the meaning is reversed.
> it should be ON like others to turn on the function.
>
> technically, the external amplifier switch controls the power-down bit
> of AC97 codec. in most cases it doesn't play any role, but it really
> controls the external amplifier on some machines (mostly laptops).
>
To fix this problem one has to type (as a superuser)
amixer -c 0 sset 'External Amplifier' unmute
alsactl store
At least this worked for me. A good idea is to backup configuration
file /var/lib/alsa/asound.state before doing this.
It would be good if this workaround can be added to kernel/alsa documentation
or, even better, to the postinstallation script. Many thanks to Takashi and
Francesco for helping me out with this.
Cheers,
Slaven
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