Comment 3 for bug 1058303

I install latest v3.6 kernel from http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.6-rc7-quantal/:
linux-image-3.6.0-030600rc7-generic_3.6.0-030600rc7.201209232235_i386.deb
linux-image-extra-3.6.0-030600rc7-generic_3.6.0-030600rc7.201209232235_i386.deb

everything looked good, but after 3rd reboot I got a black screen as described in this bug:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1029159

and a lot of errors in dmesg:
radeon 0000:00:01.0: couldn't schedule ib
[drm:radeon_cs_ib_chunk] *ERROR* Failed to schedule IB !

after that i reboot system more than 30 times but can't reproduce that again and all works fine