[Intel-gfx] [PATCH 4/4] drm/i915: enable forcewake voodoo also for gen6

[Daniel Vetter]

On Wed, Jan 25, 2012 at 02:04:00PM +0100, Daniel Vetter wrote:
> We still have reports of missed irqs even on Sandybridge with the
> HWSTAM workaround in place. Testing by the bug reporter gets rid of
> them with the forcewake voodoo and no HWSTAM writes.
> 
> Because I've slightly botched the rebasing I've left out the ACTHD
> readback which is also required to get IVB working. Seems to still
> work on the tester's machine, so I think we should go with the more
> minmal approach on SNB. Especially since I've only found weak evidence
> for holding forcewake while waiting for an interrupt to arrive, but
> none for the ACTHD readback.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=45181
> Tested-by: Nicolas Kalkhof nkalkhof()at()web.de
> Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>

Another bug reporter just confirmed that this patch gets rid of 'missed
IRQ?' quasi-hangs on snb. Unfortunately there's still another bug left to
squash, which hangs the gpu ...

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=45332
-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48