Can you please boot with drm.debug=0xe added to your kernel cmdline, reproduce the issue (up to the stuck task backtrace) and then grab the complete dmesg? Also retesting on 3.12 might be worth a shot.
Can you please boot with drm.debug=0xe added to your kernel cmdline, reproduce the issue (up to the stuck task backtrace) and then grab the complete dmesg? Also retesting on 3.12 might be worth a shot.