On affected system:
1. Load fullscreen OpenGL something which thinks fullscreen means both attached monitors. This includes kwin and warzone.
2. Kernels 2.6.37-git15 2.6.38-rc1-git2 2.6.38-rc2-git7 show expected on first monitor and complete blur on second monitor. Total messy blur. Everything works perfectly with stable 2.6.37-gentoo kernel. I do not know what happened with <=2.6.37-git15, but I do know 2.6.37-git15 kernels and later are defective.
It would be nice if someone could make two monitors work with OpenGL again (working kwin is nice).
did you update anything other than the kernel (mesa, ddx, etc.)? If it's just the kernel can you bisect?
I update git x11-libs/libdrm, x11-drivers/xf86-video-ati and media-libs/mesa frequently.
I do not know if new kernels work with older version of libdrm/video-ati/mesa, I had a recient version of those when I noticed, update to later and still no second screen so I tried an old kernel and it worken, then I tried all the newer ones mentioned.
Created attachment 43633 [details]
How totally broken fullscreen OpenGL applications look
kwin and other fullscreen opengl applications still show a total blurry mess on the second monitor as of kernel 2.6.38-rc5-git4.
Completely broken and useless.
kwin started OK with both my screens usable today.
git ati/mesa from this weekend, maby yesterday.
closing bug as fixed.