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04fee895ef
The video= parameter of the DRM drivers supports some additional flags that
the normal fb drivers do not have. They also allow to limit these flags to
specific outputs. Both things were previously undocumented.
Also the parsing of the line had some oddities:
-A lot of misplaced options were silently ignored or partly rejected instead
of stopping the parsing immediately
-The 'R' option is documented to follow the 'M' option if specified. It is not
documented that 'M' is needed to specify 'R' (also this is the case for normal
fb drivers). In fact the code is correct for normal fb drivers but wrong for
DRM ones.
The old code allowed 'R' only _before_ 'M' (since it parses backwards) and only
if 'M' is given at all which is not needed for the DRM drivers.
-the margins option ('m') was parsed but later ignored even if the later
functions support it.
-specifying multiple enable options at the same time did not lead to an error.
-specifying something bogus for horizontal resolution (i.e. other things as
digits) did not lead to an error but an invalid resolution was used.
If any errors are encountered the position of the faulting string is now
printed to the user and the complete mode is ignored. This gives much
more consistent error behaviour.
I also removed some useless assignments and changed the local flag variables
to be bool.
Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
************************************************************
* 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