Re: [Intel-gfx] [PATCH] drm/i915: Flush pipecontrol post-sync writes

Jani Nikula
2015-10-13T13:57:54Z

On Tue, 13 Oct 2015, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Tue, Oct 13, 2015 at 03:45:58PM +0300, Jani Nikula wrote:
>> On Wed, 26 Aug 2015, Chris Wilson <chris@chris-wilson.co.uk> wrote:
>> > On Wed, Aug 26, 2015 at 11:16:34AM +0200, Daniel Vetter wrote:
>> >> On Fri, Aug 21, 2015 at 04:08:41PM +0100, Chris Wilson wrote:
>> >> > In order to flush the results from in-batch pipecontrol writes (used for
>> >> > example in glQuery) before declaring the batch complete (and so declaring
>> >> > the query results coherent), we need to set the FlushEnable bit in our
>> >> > flushing pipecontrol. The FlushEnable bit "waits until all previous
>> >> > writes of immediate data from post-sync circles are complete before
>> >> > executing the next command".
>> >> >
>> >> > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
>> >> > Cc: stable@vger.kernel.org
>> >>
>> >> Do we have an igt/piglit failing somewhere (igt kinda preferred) or a
>> >> bugzilla or why is this cc: stable?
>> >
>> > I get GPU hangs on byt without flushing these writes (running ue4).
>> > piglit has examples where the flush is required for correct rendering.
>>
>> Daniel, does this satisfy your question? We've had an r-b from Ville for
>> a long time.
>
> Yeah, just add that bit to the commit message to justify cc: stable.

Pushed to drm-intel-fixes, thanks for the patch and review.

BR,
Jani.

> -Daniel
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch

--
Jani Nikula, Intel Open Source Technology Center