How to debug drm/kernel on system freeze

[Alex Deucher]

2011/6/11 Frederik Vogelsang <frederik.vogelsang at googlemail.com>:
> Hi,
>
> sorry for the late reply, but I was testing various options intensively.
>
> 2011/5/3 Michel Dänzer <michel at daenzer.net>:
>> *If* the kernel produes any more output, you might get at it with a
>> serial console or netconsole.
> netconsole is what I was looking for - thanks. But unfortunately the
> kernel does not print *any* output when the system freezes. No stack
> trace, nothing (not even with DRM debug).
>
>
> 2011/5/3 Alex Deucher <alexdeucher at gmail.com>:
>> The problem with with a lot of lockups is that they don't produce any
>> special output.
> Yeah, I noticed that :(
>
>> It would help to pinpoint what module is causing the problem.  Try setting:
>> Option "NoAccel" "True"
> This option works.
>
>> Next you can try removing that option and disabling EXA composite:
>> Option "EXANoComposite" "true"
> With EXANoComposite=true I also did not get any freezes at all. I've
> testet this for a long time (one month) and it worked (with both r300c
> and r300g).
>
> As soon as I remove the "EXANoComposite" option I am getting these
> freezes again (with r300c, 300g, plain gallium software rasterizer,
> llvm software rasterizer and mesa software rasterizer).
>
> Any ideas or patches I could try?
>

Make sure your kernel has this patch:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=b7d8cce5b558e0c0aa6898c9865356481598b46d

Alex

>
> Regards,
> Frederik
>