The docs warn that to position the cursor such that no part of it is
visible on the pipe is an undefined operation. Avoid such circumstances
upon changing the mode, or at any other time, by unsetting the cursor if
it moves out of bounds.
"For normal high resolution display modes, the cursor must have at least a
single pixel positioned over the active screen.” (p143, p148 of the hardware
registers docs).
Fixes:
Bug 24748 - [965G] Graphics crashes when resolution is changed with KMS
enabled
https://bugs.freedesktop.org/show_bug.cgi?id=24748
v2: Only update the cursor registers if they change.
v3: Fix the unsigned comparision of x,y against width,height.
v4: Always set CUR.BASE or else the cursor may become corrupt.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reported-by: Christian Eggers <ceggers@gmx.de>
Cc: Christopher James Halse Rogers <chalserogers@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Eric Anholt <eric@anholt.net>
************************************************************
* 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
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