Pageflipping bugs in drm-next on at least Ironlake and Ivybridge.

[Chris Wilson]

On Wed, Jul 06, 2016 at 12:17:55PM +0200, Mario Kleiner wrote:
> Since i pulled the current drm-next tree i see strong flicker and
> visual corruption during pageflipping, both in my own app, but also
> in KDE4 and KDE5 Plasma with desktop composition enabled. This
> happens on both Intel HD Ironake mobile (Apple MBP 2010) and HD-4000
> Ivybridge mobile (Apple macMini 2012).
> 
> It looks like page flips are not waiting properly for rendering to
> complete, showing partially rendered frames at flip time.
> 
> If i revert Daniel's commit that switches legacy pageflips from the
> old code path to the atomic code, all problems disappear, so
> apparently the atomic code for Intel is not quite ready at least on
> those parts?

Exactly right, we've reverted the enabling patch for the time being.
Daniel Stone has spotted the likely problem, but we also want to review
the handling of state/old_state to see if the same problem has cropped
up elsewhere.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre