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

[chris]

On Thu, 2011-06-16 at 20:00 -0400, Robert P. J. Day wrote:
> On Sat, 18 Jun 2011, chris wrote:
> 
> > On Thu, 2011-06-16 at 19:16 -0400, Robert P. J. Day wrote:
> > > technically speaking, not a ubuntu issue but i'm hoping someone here
> > > can point me in the right direction.  under my earlier
> > > 2.6.39-rc7-dirty kernel on 10.10, sound on my gateway NV79 laptop just
> > > plain worked.  under that earlier kernel, here's the output of a
> > > couple commands:
> > >
> > > $lspci -v
> > > 00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 05)
> > >         Subsystem: Acer Incorporated [ALI] Device 031c
> > >         Flags: bus master, fast devsel, latency 0, IRQ 42
> > >         Memory at d4400000 (64-bit, non-prefetchable) [size=16K]
> > >         Capabilities: <access denied>
> > >         Kernel driver in use: HDA Intel
> > >         Kernel modules: snd-hda-intel
> > >
> > > $ cat /proc/asound/card0/codec* | grep Codec
> > > Codec: Realtek ALC272X
> > > Codec: Conexant ID 2c06
> > > Codec: Intel IbexPeak HDMI
> > >
> > >   also, System->Preferences->Sound, "Hardware" showed:
> > >
> > >     Internal Audio
> > >     1 Output / 1 Input
> > >     Analog Stereo Duplex
> > >
> > > and "Test Speakers" worked fine, as did all other sound-related apps.
> > >
> > >   now, having updated my kernel source and built and booted to a new
> > > kernel on 11.04:
> > >
> > > $ uname -r
> > > 3.0.0-rc3-00165-gf8f44f0-dirty
> > > $
> > >
> > > my sound has vanished.  no youtube, no playing music CDs, etc.
> > >
> > >   the output of "lspci -v" and checking under /proc as above shows
> > > exactly the same output, but if i go under System->Preferences->Sound
> > > and look under the "Hardware" tab, it's *empty*, so there's nothing to
> > > select and test.
> > >
> > >   based on what i've read, it seems that one possible solution is to
> > > edit the file /etc/modprobe.d/alsa-base.conf and, in my case, add a
> > > line of the form
> > >
> > >   options snd-hda-intel model=????
> > >
> > > then run "sudo alsa force-reload" to reload all the modules.  but
> > > i've tried several choices: generic, auto, and a few others, and
> > > nothing's worked.
> > >
> > >   i'm open to suggestions.  clearly, it's a very bad thing that
> > > there's nothing listed under sound hardware, but i don't know how to
> > > reconfigure to get it back.  thoughts?
> >
> > I found that it needed options snd-hda-intel model=laptop to get it
> > working for me
> 
>   tried that, no success.
> 
> rday
> 
> -- 
> 
On one laptop I did have to use model=    and the model number of the
chip.  I think it was an hp8730w.

It was dual boot, so I got the model number from windows device manager.
The hp web site is fairly good, and should have the information on the
sound chip.  Some of the intel chips are I believe actually made by
realtek.