[PATCH xserver 3/3] present: Only requeue if target MSC is not reached after an unflip

[Chris Wilson]

On Wed, Feb 24, 2016 at 04:52:59PM +0900, Michel Dänzer wrote:
> From: Michel Dänzer <michel.daenzer at amd.com>
> 
> While present_pixmap decrements target_msc by 1 for present_queue_vblank,
> it leaves the original vblank->target_msc intact. So incrementing the
> latter for requeueing resulted in the requeued presentation being
> executed too late.

My mistake. Yes, the local target_msc is decremented but after
vblank->target_msc is assigned.
 
> Also, no need to requeue if the target MSC is already reached.
> 
> This further reduces stutter when a popup menu appears on top of a
> flipping fullscreen window.
> 
> Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>

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

-- 
Chris Wilson, Intel Open Source Technology Centre