[Intel-gfx] [PATCH] intel/gtt: unmap pages after rewriting GTT table.

[Dave Airlie]

On Tue, Jan 11, 2011 at 11:28 PM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> On Tue, 11 Jan 2011 11:17:16 +1000, Dave Airlie <airlied at gmail.com> wrote:
>> This fixes a regression caused by the GTT rework that
>> 450f2b3d51025a1749b694ee13f0e4e23ed58750 is part off.
>>
>> On my ILK laptop with DMAR enabled I was seeing the occasional
>> DMAR warning.
>>
>> The ordering in the previous code was to rewrite the GTT table
>> before unampping the pages and that makes sense to me.
>
> Dave you mentioned on IRC that this is not sufficient to quieten DMAR,
> right?  The unbind+unmap looks safer than unmap+unbind, so that seems to
> be a good patch regardless.
> -Chris
>

This patch needs to go to stable as it fixes 2.6.37 DMAR problems.

Separate problem is d-i-n, this code has changed around but the same idea
still applies and it fixes this particular problem. However d-i-n has
introduced another
DMAR error that I posted in the dmesg earlier. Granted d-i-n also
hangs and crashes
GPU randomly.

Dave.
> --
> Chris Wilson, Intel Open Source Technology Centre
>