Re: radeon KMS causes GART Table Walk Errors (was: K8 ECC error with linux-2.6.32)

[Jerome Glisse <glisse@freedesktop.org>]

On Wed, Dec 16, 2009 at 03:58:30PM +0100, Johannes Hirte wrote:
> Am Mittwoch 16 Dezember 2009 08:14:43 schrieb Borislav Petkov:
> > On Tue, Dec 15, 2009 at 11:00:46PM +0100, Johannes Hirte wrote:
> > > This patch (as the BIOS option) will only disable the error reports. The
> > > error itself will still occur, right? So necessary to find out why the
> > > radeon driver trigger this error.
> > 
> > Because the graphics driver does aperture accesses with no
> > matching GART translation, and the hw generates mchecks for
> > that. The whole story on GART table walk errors is in section
> > "13.10.1 GART Table Walk Error Reporting" in the document here:
> > http://support.amd.com/us/Processor_TechDocs/32559.pdf
> > 
> > I can't say for sure about your BIOS, but if it is done as described in
> > the abovementioned section, the BIOS option should disable logging of
> > the error, which implies reporting too.
> > 
> > The patch is still needed for machines that do not have that BIOS
> > option.
> 
> Disabling in BIOS doesn't made any difference. The errors were still reported. 
> Your patch disabled it. But I think this will make work harder for driver 
> developers as they won't get this error anymore. Could this be made changeable 
> on runtime/boottime?
> 
> I've added drm people to CC as they're responsible for this error.
> 
> 
> regards,
>   Johannes

More context would be usefull. Are you using KMS ? If so is your userspace
KMS capable ? Does this GART error happen all the time or only after sometimes
or when doing somethings specific ?

Cheers,
Jerome