Created attachment 101360 [details]
Image showing the artifact

I have updated the kernel to 3.16-rc1 and got some screen artifacts.
I have bisected the problem and found that the commit
1aab5514ca9604e0263f658a067da0189c86a35b (drm/radeon: rework page flip handling
v3) is causing these artifacts.
I am attaching some images to show these artifacts.
There is also a artifact in steam logo inside Portal 2 (the background texture
seems to disapear) that does not happen in commit just before
(1a0e79184132c5dc0e03a4047eacecc52c24deae).
I got 2 freezes too. The computer does not respond anymore, I can't switch to
console and after some seconds the computer reboots.
But I not sure if this problem is in this commit
(1aab5514ca9604e0263f658a067da0189c86a35b).