Bugzilla – Bug 30295
[Piketon] extended desktop shifts left with compiz, in 18.104.22.168 kernel
Last modified: 2010-12-20 05:46:03 UTC
Bug detailed description:
we used two monitors, one is VGA and the other is DP. In extended mode, they display normally without compiz. But once compiz run, desktop become wrong(reference to attachment).
And we found that if we change kernel to 2.6.34,the issue disappeared.
1. VGA and DP display plugged in
2. start X and gnome desktop without compiz
3. xrandr --output DP1 --left-of VGA1
4. run compiz
Created attachment 38832 [details]
extended desktop. The right edge of the right monitor(VGA) is wrong
Created attachment 38833 [details]
Note the right edge.
1. sw screen shot shows correctly, not revealing this problem.
2. mouse effects in the "expected" location, i.e. right offset to the wrongly "appeared" display.
(suggests not to block Q3 release)
This should be fixed with:
Author: Chris Wilson <email@example.com>
Date: Sun Aug 8 10:15:59 2010 +0100
drm/i915: Fix offset page-flips on i965+
i965 uses the Display Registers to compute the offset from the display
base so the new base does not need adjusting when flipping. The older
chipsets use a fence to access the display and so do perceive the
surface as linear and have a single base register which is reprogrammed
using the flip.
Signed-off-by: Chris Wilson <firstname.lastname@example.org>
Cc: Jesse Barnes <email@example.com>
Reported-by: Marty Jack <firstname.lastname@example.org>
Reviewed-by: Jesse Barnes <email@example.com>
Hmm, but wasn't proposed to stable.
The patch should be in 2.6.36-rc4. Yi, can you verify?
*** Bug 30529 has been marked as a duplicate of this bug. ***
The issue doesn't come out with 2.6.36-rc4 kernel.
let Chris to decide closing this.
I can confirm that with latest kernel this is fixed.
I left this bug open in case anybody felt inspired to propose the patch for earlier stable kernels... However, that did not happen and now we have a stable release with the bug fix, I'm closing this report. Thanks.
that makes sense.
I think I am experiencing the same with kde, yet using
xrandr --output VGA1 --auto --above LVDS1
in this case, I get a vertical skew on the primary screen whose bottom part gets filled with garbage.
If I understand correctly, this is fixed in the kernel part of the Intel driver.
Would it be easy to backport to 2.6.35? Is it in a modularized part of the kernel that can be recompiled independently (e.g. the i915 module)?
I am asking to see if it can somehow be possibile to push a fix into distros such as ubuntu that tend to be a bit conservative about kernel changes.