Akemi Yagi amyagi at gmail.com wrote:

On Wed, Aug 25, 2010 at 2:39 PM, Glenn Eychaner <geychaner at mac.com> wrote:

...

So, just today I noticed a problem with kernel 2.6.18-194 (CentOS 5.5) on several Intel DP965LT systems; the system beeps (such as terminal beeps) are no longer passed through to the external speakers. This is a problem because in our situation the boxes are distant from their monitor/keyboard, the system speaker on this motherboard is extremely weak, and there are no system speaker header pins on the motherboard. The problem goes away if I revert the system to 2.6.18-164 with no other changes. I looked through the list archives and searched the web for other people who have encountered this, but it's pretty specific (and hard to search for "system beep"!)

Does it have Nvidia controllers? If so, it may be related to: http://bugs.centos.org/view.php?id=4335

Nope. It has a PCI NVidia graphics card, but the tech specs for the board (page 12) show Intel chipsets (as expected). http://downloadmirror.intel.com/15049/eng/DP965LT_TechProdSpec.pdf Besides, I tried adding the "enable_msi=0" to that line of modprobe.conf, and it didn't make any difference.

...

Is there someplace can I find *detailed* release notes on the differences between -164 and -194 kernels to help in looking for the problem, pinning it down, and submitting a patch (and/or building my own kernel), or should I just download the SRPMS and dig in?

You can find kernel changelog diffs here (maintaind by Alan Bartlett): http://www.centos.toracat.org/ajb/kernel-clog-diff/

Wow. Considering I need to look at everything from 164-15 to 194-3, that's a lot of heavy reading and searching.

-G. -- Glenn Eychaner (geychaner@lco.cl) Telescope Systems Programmer, Las Campanas Observatory