Comment 16 for bug 399821

I had more time than I orginally thought today to do some further testing (and lots of googling) and have made some progress.

The mainline 2.6.31 rc3 kernel worked correctly. I can boot the problematic rc3 kernel by passing the nomodeset parameter.

If I pass the VGA = ask parameter to the rc2 kernel I get a list of VGA modes. If I do the same thing with the rc3 kernel I get the same list of VGA modes plus a second set of VESA modes (none of which appear to work).

That led me to this bug:

https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-vesa/+bug/401214

and I've tried turning debugging on as suggested with:

echo 1 | sudo tee /sys/module/drm/parameters/debug

Although didn't get any extra output.

A little more searching led to a very similar looking bug report:

http://bugs.freedesktop.org/show_bug.cgi?id=20115

with a patch attached at comment #50. I'm now at a point where I probably need to learn how to patch a kernel which I won't get chance to do today. However, at least it looks like this has been narrowed down to a problem with KMS. Alternatively, I could be headed in completely the wrong direction as this stuff is a bit over my head. Let me know if there's anything else I can try. I'll post any further results.

Twig.