Files
linux-apfs/drivers/gpu/drm
Chris Wilson 19b2dbde57 drm/i915: Restore fences after resume and GPU resets
Stéphane Marchesin found that fences for pinned objects (i.e. the
scanout) were not being restored upon resume, leading to corruption on
the display and reference counting issues. This is due to a bug in

commit 312817a39f [2.6.38]
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon Nov 22 11:50:11 2010 +0000

    drm/i915: Only save and restore fences for UMS

that zapped the pinned fences even though they were in use.
Fortuitously, whilst we forced a VT switch during suspend and resume,
no fences were ever pinned at the time. However, we now can do
switchless S3 transitions and so the old bug finally surfaces.

Reported-by: Stéphane Marchesin <marcheu@chromium.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Stéphane Marchesin <marcheu@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-06-16 01:10:45 +02:00
..
2013-05-31 12:45:09 +10:00
2013-04-30 15:15:58 +02:00
2013-04-30 10:02:25 +10:00
2013-04-26 10:20:00 +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