Created attachment 75272 [details] [review]
Possible fix for R600 hw deadlock

Patch has been tested on a system with AMD K8 CPU and Radeon AGP card (AMD
RV670 / Radeon HD 3850) with both 3.6.11-030611-generic kernel (from Ubuntu
kernel PPA mainline) and kernel built from recent drm-fixes git in the testing.
This patch may also be relevant to reported Bug 47116 .