Xorg freezes with Radeon Xpress 1200/1250/1270 chipset

[Yuri]

I posted this PR https://bugs.freedesktop.org/show_bug.cgi?id=66711 , 
and there is no resolution or workaround.
Linux randomly freezes 1-2 times a day.
Somebody there suggested that KMS might be related, since KMS-free 
FreeBSD version of xorg works fine on the same HW.

Is there any workaround for this  problem?
Any way to disable KMS? Or any parameters I can try tweaking to at least 
reduce the chance of freezing?

Yuri