Files
linux-apfs/drivers/gpu/drm
Chris Wilson b66d842467 drm/i915/sdvo: Restore guess of the DDC bus in absence of VBIOS
If the VBIOS tells us the mapping of the SDVO device onto the DDC bus,
use it. However, if there is no VBIOS available that mapping is
uninitialised and we should fallback to our earlier guess.

Fix regression introduced in b1083333 (which in turn is a fix for the
regression caused by the introduction of this guess, 14571b4).

References:

  Bug 29499 - [945GM] Screen disconnected because of missing VBIOS
  https://bugs.freedesktop.org/show_bug.cgi?id=29499

  Bug 15109 - i945GM fails to detect EDID on DVI port
  https://bugzilla.kernel.org/show_bug.cgi?id=15109

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reported-and-tested-by: Paul Neumann <paul104x@yahoo.de>
Cc: Adam Jackson <ajax@redhat.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: stable@kernel.org
2010-09-07 11:14:16 +01:00
..
2010-08-04 09:46:06 +10:00
2010-05-18 15:57:05 +10:00
2010-08-10 10:47:00 +10:00
2010-05-18 15:57:05 +10:00
2010-08-10 08:20:20 +10:00
2010-08-20 08:48:34 +10:00
2010-08-04 09:46:06 +10:00

************************************************************
* 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