Comment 43 for bug 877789

(In reply to comment #27)
> (In reply to comment #26)
> > It seems that problem does not occur in current drm-radeon-testing
> > (9e67e5b1a6fd4bdca48a9c267386afb236d08783). At least sound does not skips.
>
> I myself don't have the possibility to test this at the moment. I will only
> have access to the laptop involved in about 3 weeks.
> But maybe Oyvind could this the drm-radeon-testing branch on his laptop?
>
> And if it does solve the problem, we should bisect to find out what does solve
> this problem.

Assuming you mean this branch:
http://git.kernel.org/?p=linux/kernel/git/airlied/drm-2.6.git;a=shortlog;h=refs/heads/drm-radeon-testing

I compiled the branch head and gave it a spin. KMS performance is noticeably better compared to 2.6.32(+drm2.6.33)-kernel in Ubuntu. However I only had to open 20-25 windows and do some jiggly Compiz effects to cause:
1. Severe audio skipping/crackling whenever something was moving, changing, minimizing, maximizing, etc.
2. Wireless was extremely unstable, in fact I add to boot back into Lucid kernel to write this comment, because it kept falling down. Of course, that might just be the kernel itself, I don't know.

Conclusion is that nothing is better on my hardware with this kernel, except the KMS performance (Compiz feels somewhat snappier when window count is high).

So it's back to good old UMS and DFS-corruption for me :) :/ ...