loading drm crashes system

[Scott Bennett]

Robert Huff <roberthuff at rcn.com> wrote:

> >   > Niclas Zeising asks:
> >   > > When did it stop working?
> >   > 
> >   > September ... I _think_.
> >   
> >   Yeah, that sounds about right.
> >   
> >   There are known issues with Radeon cards, they were quite well
> >   supported a year ago, then something got broken.  I've promised to
> >   bisect this and find the cause, but there were several syscall-related
> >   changes in -CURRENT though the course of the last year, so bisecting
> >   just the kernel is not enough (machine won't get to login prompt if
> >   the userland does not match), which cripples the process.
> >   
> >   I still intend to take this quest, just not sure when. :(
>
> 	Expanding on "September ... I think":
> 	Try September 26 as a reference date.  Sometime close to then I
> a) updated world+kernel to the latest version of current, so also b)
> updated to the latest drm-current-kmod and gpu-firmware.
> 	Question: is there a way for the less sophisticated user <waves>
> to tell whether the cause is in the drm knod or the firmware kmod?
>
     It may well be in both.  See PR #247441, in which the firmware hangs the
GPU, the drm kmod then notices that the GPU has stopped responding, waits 10+ s,
then branches into the BIOS reset routine.  Both the hang and the drm kmod
response are bugs.


                                  Scott Bennett, Comm. ASMELG, CFIAG
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