[BUG][BISECTED][RESENT] Ogre3d produces black screen on Intel 965GM

[Dariush F. <da...@fo...>]

Hi everyone,

applications using the ogre3d library (www.ogre3d.org) only show
black screens instead of fancy 3D graphics on current 2.6.32-rc8.
On 2.6.31 they worked fine.

In the error case the kernel reports errors like this:

[drm:i915_gem_object_pin_and_relocate] *ERROR* Relocation beyond target
object bounds: obj ffff8800d74c3b40 target 91 delta 4096 size 4096.
[drm:i915_gem_execbuffer] *ERROR* Failed to pin buffer 105 of 105, total
8699904 bytes: -22
[drm:i915_gem_execbuffer] *ERROR* 1172 objects [109 pinned], 57942016
object bytes [24915968 pinned], 55570432/260308992 gtt bytes
[drm:i915_gem_object_pin_and_relocate] *ERROR* Relocation beyond target
object bounds: obj ffff8800d74c3b40 target 12 delta 16384 size 16384.
[drm:i915_gem_execbuffer] *ERROR* Failed to pin buffer 26 of 26, total
6688768 bytes: -22
[drm:i915_gem_execbuffer] *ERROR* 1172 objects [30 pinned], 57942016
object bytes [22904832 pinned], 55570432/260308992 gtt bytes
[drm:i915_gem_object_pin_and_relocate] *ERROR* Relocation beyond target
object bounds: obj ffff8800d74c3b40 target 101 delta 4096 size 4096.
[drm:i915_gem_execbuffer] *ERROR* Failed to pin buffer 26 of 26, total
5009408 bytes: -22
[drm:i915_gem_execbuffer] *ERROR* 1173 objects [30 pinned], 58204160
object bytes [21225472 pinned], 55832576/260308992 gtt bytes
[drm:i915_gem_object_pin_and_relocate] *ERROR* Relocation beyond target
object bounds: obj ffff8800d74c3b40 target 18 delta 4096 size 4096.
[drm:i915_gem_execbuffer] *ERROR* Failed to pin buffer 23 of 23, total
4550656 bytes: -22
[drm:i915_gem_execbuffer] *ERROR* 1173 objects [27 pinned], 58204160
object bytes [20766720 pinned], 55832576/260308992 gtt bytes
[drm:i915_gem_object_pin_and_relocate] *ERROR* Relocation beyond target
object bounds: obj ffff8800d74c3b40 target 91 delta 4096 size 4096.
[drm:i915_gem_execbuffer] *ERROR* Failed to pin buffer 133 of 133, total
7897088 bytes: -22


I bisected it down to the following commit:

commit cd0b9fb400ba775737bdc3874c4cbee4047e66d8
Author: Chris Wilson <ch...@ch...>
Date:   Tue Sep 15 23:23:18 2009 +0100

    drm/i915: Check that the relocation points to within the target

    Eric noted a potential concern with the low bits not being strictly used
    as part of the absolute offset (instead part of the command stream
to the
    GPU), but in practice that should not be an issue.

    Signed-off-by: Chris Wilson <ch...@ch...>
    Tested-by: Andy Whitcroft <ap...@ca...>
    Cc: Eric Anholt <er...@an...>
    CC: st...@ke...
    Signed-off-by: Jesse Barnes <jb...@vi...>



Reverting the commit manually makes the problem disappear.

cheers
Dariush


Platform: AMD64
Distro: Debian testing
GPU: Intel 965GM
xserver: 1.6.5
xorg-intel: 2.9.0
libdrm: 2.4.14
OGRE: 1.6.4