[Intel-gfx] [PATCH] drm/i915: Work-around garbage DR4 from UXA

[Daniel Vetter]

On Tue, May 13, 2014 at 01:25:49PM +0100, Chris Wilson wrote:
> On Tue, May 13, 2014 at 02:02:07PM +0200, Daniel Vetter wrote:
> > Somehow UXA submits a completely bogus DR4 value since essentially
> > forever. It was originally introduced in
> > 
> > commit bade7d7d2505a10a8a7d24b084aff9742e2d6d64
> > Author: Eric Anholt <eric at anholt.net>
> > Date:   Fri Jun 6 14:03:25 2008 -0700
> > 
> >     Use the DRM for submitting batchbuffers when available.
> > 
> > and dutifully copied around ever since. Since we want to keep the
> > general dirt catching around just special case the UXA value.
> > 
> > This regression was introduced in
> > 
> > commit 9cb346648d9c529eccc5c7f30093e82d37004e37
> > Author: Daniel Vetter <daniel.vetter at ffwll.ch>
> > Date:   Thu Apr 24 08:09:11 2014 +0200
> > 
> >     drm/i915: Catch dirt in unused execbuffer fields
> > 
> > v2: Pimp commit message a bit and remove the double space.
> > 
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78494
> > Cc: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: Jörg Otte <jrg.otte at gmail.com>
> > Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> 
> To be fair, it is a sensible value if one supposes a Region style API to
> cliprects. Under that API, DR[14] define the extents of the clip region,
> and ((0,0), (0,0)) [DR1==DR4==0] would mean all clipped, do not draw
> anything.

Hm right. I've added this to the commit message.

> Anyway, as far as fixing up the EINVAL,
> Acked-by: Chris Wilson <chris at chris-wilson.co.uk>

And merged the patch to dinq.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch