[Intel-gfx] [PATCH] drm/i915/skl: Use correct use counters for force wakes

[Daniel Vetter]

On Tue, Sep 30, 2014 at 04:58:54PM +0100, Tvrtko Ursulin wrote:
> 
> 
> On 09/30/2014 03:57 PM, Chris Wilson wrote:
> >On Tue, Sep 30, 2014 at 03:08:02PM +0100, Tvrtko Ursulin wrote:
> >>From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> >>
> >>Write and reads following the block changed use engine specific use counters
> >>and unless that is matched here force wake use counting goes bad. Same
> >>force wake is attempted to be taken twice which leads to at least time outs.
> >>
> >>NOTE: Depending on feedback from hardware designers it may not be necessary
> >>to grab force wakes on Gen9 here. But for Gen8 it is needed due to a race
> >>between RC6 and ELSP writes.
> >>
> >>v2: Added blitter force wake engine and made more future proof.
> >>     Added commit note.
> >
> >Speaking of futureproofing, what did you think of my patch to remove the
> >duplicated counting logic?
> 
> [For reference it is called "[PATCH] drm/i915: Reduce duplicated forcewake
> logic".]
> 
> Disclaimer: I don't know this code that well - only had to dig into it a few
> days back when I hit this bug which resulted in my patch.
> 
> But from a glance your patch does make it look cleaner and indeed more
> future proof (much better separation between platform specific and generic).
> Does it need a proper review to move it forward?

Yes. Volunteered?

And when you review pls reply with a blurb in case the existing commit
message from Chris doesn't fully cover the bug you've stumbled over, so
that lazy me can just copy-paste that while applying ;-)

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch