[CentOS] kernel-2.6.18-128.7.1.el5.i686 update breaks AMD onboard sound

Sat Aug 29 13:06:09 UTC 2009
Mike A. Harris <mharris at mharris.ca>

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The new kernel-2.6.18-128.7.1.el5.i686 kernel breaks audio support on my
onboard audio on an AMD Solo motherboard.

00:07.5 Multimedia audio controller: Advanced Micro Devices [AMD]
AMD-8111 AC97 Audio (rev 03)

After upgrading to the new kernel from kernel-2.6.18-128.4.1.el5.i686, I
quickly noticed audio not working in Flash in firefox, then after some
tinkering realized audio didn't work at all, not even the mixer,
although the sound card drivers were loaded.

I ran system-config-soundcard and got no audio as well, it was unable to
open the device.  Running ogg123 from the commandline gave me an ALSA
error about being unable to open a sound device before SEGV'ing.  An
strace revealed that /dev/snd/* was missing a device node.

I rebooted into the prior kernel (kernel-2.6.18-128.4.1.el5.i686) and
sound came back.  The missing device node was back, along with several
others that are missing in the new kernel as well.

Here is the kernel rpm changelog between the working and non-working
kernels:


* Mon Aug 24 2009 Karanbir Singh <kbsingh at centos.org>
[2.6.18-128.7.1.el5.centos]
- - Roll in CentOS Branding

* Wed Aug 19 2009 Jiri Pirko <jpirko at redhat.com> [2.6.18-128.7.1.el5]
- - [net] prevent null pointer dereference in udp_sendmsg (Vitaly
Mayatskikh) [518047 518043] {CVE-2009-2698}

* Sat Aug 15 2009 Jiri Pirko <jpirko at redhat.com> [2.6.18-128.6.1.el5]
- - [net] make sock_sendpage use kernel_sendpage (Jiri Pirko ) [517445
516955] {CVE-2009-2692}

* Tue Aug 04 2009 Jiri Pirko <jpirko at redhat.com> [2.6.18-128.5.1.el5]
- - [dlm] free socket in error exit path (David Teigland ) [515432 508829]


It'd be nice to try the Red Hat kernel to see if it is a CentOS specific
glitch or not, but I suspect it isn't.  Can't do that easily unfortunately.

Are there existing CentOS builds of the 128.5/128.6 kernels archived
somewhere?

I had a quick scan through Red Hat and CentOS bugzillas, and did not see
anything reported about this yet.

I'm still investigating the problem before filing a bug report myself,
but wanted to get some feedback from other users to determine how wide
the problem might be, and hopefully narrow it down.



- --
Mike A. Harris
http://mharris.ca  |  https://twitter.com/mikeaharris

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