On Thu, 11 Oct 2012 18:12:18 +1000, Dave Airlie <airlied at gmail.com> wrote: > On Thu, Oct 11, 2012 at 5:53 PM, Chris Wilson <chris at chris-wilson.co.uk> wrote: > > On Thu, 11 Oct 2012 14:30:29 +1000, Dave Airlie <airlied at gmail.com> wrote: > >> From: Dave Airlie <airlied at redhat.com> > >> > >> While playing with MPX and sw cursor I noticed page flips won't > >> end up misrendering some bits, so the sw cursor was replacing the > >> bits on the wrong pixmap. > >> > >> Fix the damage handling to be correct and append damage before swapping > >> the pointers and process damage after. > >> > >> This fixes misrendering with MPX cursors under a fullscreen compositor, > >> that pageflips. > > > > Wow, what magic is this? The created region is the same and > > front->drawable left unmodified by the exchange. The exchange only > > manipulates the devPrivates and has not other side effects. The only > > uncertain quantity there is the intel_glamor_exchange_buffers()... > > > > So the change is that we append the same damage to the same drawable > > earlier, yet still process that damage at the same time, with no > > apparent side-effects between the two operations. I'm just not > > understanding why this has any effect. > > Hence why I didn't do it right in the first place, I thought I > understood how damage worked :-) > > We have pre-rendering damage reporting and post-rendering damage > reporting!, so sw cursors really wants it before the fact so it can > copy the area out underneath itself, > > damage append will process the pre-damage stuff, and pending will > process post-damage hooks. Thanks for the explanation, I had forgotten that not everything was PostOp reported! commit dadffd0061e2b14db397608e3cedfe9c76e546c8 Author: Dave Airlie <airlied at redhat.com> Date: Thu Oct 11 14:30:29 2012 +1000 intel: fix fullscreen damage posting on pageflip -Chris -- Chris Wilson, Intel Open Source Technology Centre