Files
Jani Nikula 1bb6f0ef0b drm/i915: do not default to 18 bpp for eDP if missing from VBT
commit 9a30a61f35 upstream.

commit 500a8cc466
Author: Zhenyu Wang <zhenyuw@linux.intel.com>
Date:   Wed Jan 13 11:19:52 2010 +0800

    drm/i915: parse eDP panel color depth from VBT block

originally introduced parsing bpp for eDP from VBT, with a default of 18
bpp if the eDP BIOS data block is not present. Turns out that default seems
to break the Macbook Pro with retina display, as noted in

commit 4344b813f1
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Aug 10 11:10:20 2012 +0200

    drm/i915: ignore eDP bpc settings from vbt

Since we can't ignore bpc settings from VBT completely after all, get rid
of the default. Do not clamp eDP to 18 bpp by default if the eDP BDB is
missing from VBT.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Henrik Rydberg <rydberg@euromail.se>
[danvet: paste in the updated commit message from irc.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-01-03 03:33:48 +00:00
..

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