Linux 2.6.39-rc3

[Alex Deucher]

On Fri, Apr 15, 2011 at 10:33 AM, Joerg Roedel <joro at 8bytes.org> wrote:
> On Fri, Apr 15, 2011 at 03:16:50PM +0200, Ingo Molnar wrote:
>> Ok, but how did the allocation changes start triggering this error in
>> v2.6.39-rc1? There must still be some layout specific thing here, right?
>> Do we understand the details of that as well?
>
> No, I must admit that I lack enough knowledge about the GPU hardware to
> make an guess how this tanslation-request happened. All I can tell is
> the address that was reported in the MCE, it is 0xa0001000 (==the second
> page of the GART aperture).
>
> Maybe Alex can help here. Alex, may it be possible that the GPU
> generates DMA requests in the GTT area before the GTT is activated (or
> the activation is completed)? Or can you imagine any other reason?

It shouldn't.  The driver binds a dummy page to all entries in the
table at init time and whenever the actual pages are unbound.

Alex