Graphics: RV620/M82 Mobility Radeon HD 3450/3470
Kernel: 3.11.0-12-agd5f from mesa-git repo 
Mesa: ati-dri-git-57713.f2be639 from mesa-git repo
OS: Arch
ARCH: x86_64
Other: KDE 4.11 rc1

I installed mesa and linux packages from mesa-git repo, the linux-agd5f
contains the lates patches. The system booted successfully 3 out of 4 times,
and the temp of GPU is actually a little bit lower than before, about 3-4C（env
temp 35C）. But same as Sergey posted, the X respose is slow, about 1-2s
delayed.

Here is my dmesg of drm and radeon.