Comment 65 for bug 727620

I have a Dell Aspire Timeline X 4820TG with Radeon HD5650 and integrated intel graphics.

This bug used to bugger me about every second boot, but after installing tons of different kernels it's actually been more sporadic. I don't know whether that is because I spend more time in the GRUB-menu, clicking to Previous versions and then choosing 2.6.38-8.

Anyways, I added the drm.debug=0x0e for all kernels and kept booting till I got some good and bad boots. Chronologically I had 1 good, 3 bad and 1 good boot, but in the attached kern.log it only shows 1 good, 1 bad, 1 good. In all the bad boots it stopped with a completely black screen (no backlight) but I was able to switch xserver (or something) by pressing Alt+F1, Alt+F2 and Alt+F7. The system did not respond to Ctrl-Alt-Del but printed some SAK line when pressing AltGr+SysRq+K without doing anything.

The last line in one terminal on all bad boots was this:
[drm:intel_prepare_page_flip], preparing flip with no unpin work?

The last thing in the other terminal was the call trace ending with this:
[ 27.218815] RIP [<ffffffffa0569b16>] evergreen_cp_start+0x56/0xc80 [radeon]

Hope this helps, let me know if you need more info.