Files
linux/drivers/gpu/drm
Jerome Glisse a1e9ada3e1 drm/radeon/kms: R3XX-R4XX fix GPU reset code
Previous reset code leaded to computer hard lockup (need to unplug
the power too reboot the computer) on various configuration. This
patch change the reset code to avoid hard lockup. The GPU reset
is failing most of the time but at least user can log in remotely
or properly shutdown the computer.

Two issues were leading to hard lockup :
- Writting to the scratch register lead to hard lockup most likely
because the write back mecanism is in fuzy state after GPU lockup.
- Resetting the GPU memory controller and not reinitializing it
after leaded to hard lockup. We did only reinitialize in case of
successfull reset thus unsuccessfull reset quickly leaded to hard
lockup.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-04-27 09:48:16 +10:00
..
2010-02-15 11:19:14 +10:00
2010-02-23 09:46:20 +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