Bug 28976 - 2.6.35rc+ kernel gives kwin lots of flickering
Summary: 2.6.35rc+ kernel gives kwin lots of flickering
Status: RESOLVED WORKSFORME
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/Radeon (show other bugs)
Version: unspecified
Hardware: Other All
: medium normal
Assignee: xf86-video-ati maintainers
QA Contact: Xorg Project Team
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2010-07-09 03:18 UTC by Öyvind Saether
Modified: 2010-08-07 02:05 UTC (History)
0 users

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Description Öyvind Saether 2010-07-09 03:18:07 UTC 
I get huge amounts of flickering when abusing the 2.6.35rc kernels later than 2.6.35-rc3-git4 when using kwin, including 2.6.35-rc4-git4. This does not happen when downgrading to 2.6.35. Something applied after 2.6.35-rc3-git4 seems to be the problem.

abUsing Gentoos latest libdrm + xf86-video-ati + mesa and the x11 9999 git overlay makes no difference, IT'S THE KERNEL.
Comment 1 Perry3D 2010-07-09 07:38:59 UTC 
I have the same problem using the drm-radeon-testing branch of the kernel. Except i experience the problem with compiz and the task-switcher.
And i had a similar problem with the XBMC. After disabling vsync, the flickering disappeared. 

ArchLinux with libdrm-git, mesa-git and xf86-video-ati-git with a HD4850.
Comment 2 Michel Dänzer 2010-07-09 08:18:24 UTC 
(In reply to comment #1)
> I have the same problem using the drm-radeon-testing branch of the kernel.
> Except i experience the problem with compiz and the task-switcher.
> And i had a similar problem with the XBMC. After disabling vsync, the
> flickering disappeared. 

See bug 28341 - there's no synchronization between the X and Mesa drivers to defer rendering to buffers involved in a pending vsynced buffer swap, so you sometimes see an incomplete next frame.

However, AFAICT the kernel support for the broken functionality already went into 2.6.35-rc1, so I'm not sure this is the same bug... Øyvind, can you try bisecting the kernel for your problem?
Comment 3 Öyvind Saether 2010-08-07 02:05:46 UTC 
Works fine 2.6.35-git2 + current git drm+ati+mesa

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