Re: Hardware bug or kernel bug?

[David Johnson <dj@david-web.co.uk>]

On Monday 16 October 2006 11:25, Jarek Poplawski wrote:
>
> Was this lock-up effect visible during above 2.6.19-rc1 tests?

No, I've not seen anything in Linux other than the reboots, which are instant 
without any preceding lock-up.

> If not I'd try to continue linux debbuging:
> - is 2.6.19-rc1 working with "normal" config (use make oldconfig
> to "upgrade" .config),

With 2.6.19-rc1 and a normal config, I get the reboots as usual.

> - is 2.6.17 working with "minimal" config (use make oldconfig),

Yes.

> - changing one or two options at a time try to find which one makes
> the effect returns (acpi, smp...).

I've found the culprit - CPU Frequency Scaling.
With it enabled I get the reboots, with it disabled I don't. That's the same 
with every kernel version I've tried (2.6.19-rc1+rc2, 2.6.17.13 & Centos' 
2.6.9) The system was using the p4-clockmod driver and the ondemand governor.

I'm still not sure exactly what the problem is - the reboots only happen in 
the circumstances I've mentioned and are not triggered by changes in clock 
speed alone - but disabling cpufreq seems to make it go away...

Thanks for your help,
David.