[Intel-gfx] [PATCH] UXA: Wait until a pageflip actually completes to report it.

[Eric Anholt]

Chris Wilson <chris at chris-wilson.co.uk> writes:

> On Wed, May 07, 2014 at 10:44:23PM -0700, Jamey Sharp wrote:
>> On Wed, May 07, 2014 at 04:55:18PM +0100, Chris Wilson wrote:
>> > On Mon, May 05, 2014 at 11:05:07PM -0700, Jamey Sharp wrote:
>> > > UXA was reporting page-flip completion as soon as the flip was scheduled
>> > > with the kernel, instead of waiting for the kernel to indicate that the
>> > > flip had actually completed.
>> > > 
>> > > Moving the DRI2SwapComplete call to the right place fixes all of our
>> > > Piglit tests for OML_sync_control when run on xf86-video-intel/UXA,
>> > > aside from a bit of difficult-to-reproduce flakiness when using a
>> > > divisor > 1.
>> > 
>> > The violation is intentional, as it gives us triple buffering by
>> > default. It can be disabled.
>> 
>> As far as I can tell, this patch has no effect on triple-buffering. I
>> verified that by logging new_front->handle in intel_do_pageflip: It
>> rotates through three different BO's on successive flips.
>
> The patch blocks clients in GetBuffers until the swap completes,
> preventing them from rendering to the third buffer.

I don't see where the client gets blocked in a swapbuffers.  Can you
point that out?
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