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ffd93f2480
Somehow UXA submits a completely bogus DR4 value since essentially
forever. It was originally introduced in
commit bade7d7d2505a10a8a7d24b084aff9742e2d6d64
Author: Eric Anholt <eric@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 9cb346648d
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Thu Apr 24 08:09:11 2014 +0200
drm/i915: Catch dirt in unused execbuffer fields
Comment from Chris' review:
"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."
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@chris-wilson.co.uk>
Cc: Jörg Otte <jrg.otte@gmail.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
************************************************************
* For the very latest on DRI development, please see: *
* http://dri.freedesktop.org/ *
************************************************************
The Direct Rendering Manager (drm) is a device-independent kernel-level
device driver that provides support for the XFree86 Direct Rendering
Infrastructure (DRI).
The DRM supports the Direct Rendering Infrastructure (DRI) in four major
ways:
1. The DRM provides synchronized access to the graphics hardware via
the use of an optimized two-tiered lock.
2. The DRM enforces the DRI security policy for access to the graphics
hardware by only allowing authenticated X11 clients access to
restricted regions of memory.
3. The DRM provides a generic DMA engine, complete with multiple
queues and the ability to detect the need for an OpenGL context
switch.
4. The DRM is extensible via the use of small device-specific modules
that rely extensively on the API exported by the DRM module.
Documentation on the DRI is available from:
http://dri.freedesktop.org/wiki/Documentation
http://sourceforge.net/project/showfiles.php?group_id=387
http://dri.sourceforge.net/doc/
For specific information about kernel-level support, see:
The Direct Rendering Manager, Kernel Support for the Direct Rendering
Infrastructure
http://dri.sourceforge.net/doc/drm_low_level.html
Hardware Locking for the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/hardware_locking_low_level.html
A Security Analysis of the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/security_low_level.html