Created attachment 43206 [details]
dmesg with BUG and call trace
Using kernel 2.6.38_rc4, xf86-video-ati 6.14.0, Radeon 6310 (Zacate), KDE 4.4
When starting KDE the graphics will freeze before the desktop appears, possibly when kwin attempts to enable desktop effects. In dmesg, the following appears along with a call trace containing radeon_crtc_page_flip:
[ 1297.514583] BUG: unable to handle kernel NULL pointer dereference at (null)
Afterwards, the system must be rebooted to get the graphics back. Setting Option "EnablePageFlip" "false" in xorg.conf makes the problem go away.
does this patch help?
Yes, thank you. With the patch the problem is fixed.