[Intel-gfx] [PATCH 27/43] drm/i915: flush overlay regfile writes

[Daniel Vetter]

On Wed, Dec 14, 2011 at 03:24:49PM +0000, Chris Wilson wrote:
> On Wed, 14 Dec 2011 13:57:24 +0100, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> > Better be paranoid. The wmb should flush the wc writes, and
> > the chipset_flush hopefully flushes any mch buffers. There've been a
> > few overlay hangs I've never really diagnosed, unfortunately all the
> > reporters disappeared.
> 
> At which point we should just put the darn wmb into i830_chipset_flush()
> and make snark remarks about wbinvd.

Iirc I've also had reports of nutty people trying the overlay on gen3.
Maybe that got fixed with one of the domain tracking fixes, maybe not.
Given that most users of this disappeared, I've thought adding some random
lore here won't hurt and maybe it makes somebody happy ;-)
-Daniel
-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48