https://bugs.freedesktop.org/show_bug.cgi?id=29787
--- Comment #11 from Arno Schuring aelschuring@hotmail.com 2010-10-23 04:49:21 PDT --- As additional datapoint, I also experience these problems under GNOME and with just one monitor (by issuing xrandr --output DVI-0 --off). Under these circumstances, no crashes happen but the screen output gets garbled, and subsequently (when the display recovers) the DVI-0 monitor gets enabled again (as in xrandr --output DVI-0 --same-as VGA-0).
Am now running 2.6.36, still with drm.poll=0. Everything is at default priority -- which is 19 according to ps, and 20 according to top -- but a number of kernel threads (including [radeon]) are at 39(ps)/0(top). rtprio is unset for all processes.