under newer hand-rolled kernel, sound has gone away on ubuntu 11.04

[Frans Ketelaars]

On Fri, 17 Jun 2011 07:26:23 -0400, Robert P. J. Day wrote:

> On Fri, 17 Jun 2011, Frans Ketelaars wrote:
> 
>> http://ubuntuforums.org/showthread.php?t=1784313 might help.
> 
>   interesting, but the advice there doesn't seem to help.  first, as
> that thread claims, there is a new "auto-mute mode" under alsamixer with
> the 3.0 kernel, but disabling that didn't help.  (i don't have to reboot
> after that, do i?)

I wouldn't think so, but a cold boot ensures that your sound hardware 
isn't in some strange state.

Some info I found about "auto-mute mode" :
http://mailman.alsa-project.org/pipermail/alsa-devel/2011-May/039281.html

>   and further down that page, there's a suggestion that, under
> Preferences->Sound, i may have the wrong output device selected.  but
> under my 3.0 kernel, the list of output devices is entirely *empty*, so
> that doesn't help.

At least alsamixer thinks you have sound hardware :)
 
>   i know that if i reboot to my 2.6.39-rc7-dirty kernel, sound works
> just fine.  i'm just trying to figure out what changes across kernel
> reboots.

Maybe look under /proc/asound/ esp. /proc/asound/devices.

Good luck!

    -Frans