[Intel-gfx] [PATCH] drm/i915: paper over missed irq issues with force wake vodoo

[Daniel Vetter]

On Wed, Jan 04, 2012 at 06:27:40PM -0800, Keith Packard wrote:
> On Wed,  4 Jan 2012 19:40:45 +0100, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> 
> > Two things seem to do the trick on my ivb machine here:
> > - prevent the gt from powering down while waiting for seqno
> >   notification interrupts by grabbing the force_wake in get_irq (and
> >   dropping it in put_irq again).
> > - ordering writes from the ring's CS by reading a CS register, ACTHD
> >   seems to work.
> 
> If this works reliably, you'll deserve a medal...

I've removed the HWSTAM workaround on my branch and both my ivb and snb
seem to still work. So I'm still hopeful that this actually works ;-)

Ben promised to beat on it with his machines, too, but I fear Eric is way
too busy with the finishing touches for the OGL 3.0 frenzy atm.
-Daniel
-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48