Files
android_kernel_xiaomi_sm8450/drivers/gpu/drm
Hugh Dickins 88b9828735 drm/i915: fix freeze with blank screen booting highmem
x86_64 boots and displays fine, but booting x86_32 with CONFIG_HIGHMEM
has frozen with a blank screen throughout 3.16-rc on this ThinkPad T420s,
with i915 generation 6 graphics.

Fix 9d0a6fa6c5 ("drm/i915: add render state initialization"): kunmap()
takes struct page * argument, not virtual address.  Which the compiler
kindly points out, if you use the appropriate u32 *batch, instead of
silencing it with a void *.

Why did bisection lead decisively to nearby 229b0489aa ("drm/i915:
add null render states for gen6, gen7 and gen8")?  Because the u32
deposited at that virtual address by the previous stub failed the
PageHighMem test, and so did no harm.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-07-22 08:10:36 +02:00
..
2014-06-10 09:35:42 +10:00
2013-12-18 11:35:01 +10:00
2013-11-06 12:05:21 +10:00
2014-07-03 07:54:26 +10:00
2013-11-15 09:32:23 +09:00
2014-05-27 15:50:57 +10:00
2014-04-23 10:32:53 +02:00
2013-12-17 18:09:46 +01:00
2013-04-30 22:20:00 +02:00
2013-12-18 11:43:29 +10:00
2014-06-02 02:07:10 +09:00

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