From: Rafael J. Wysocki on
Alex, Dave,

I'm afraid hibernation is broken on all machines using radeon/KMS with r300
after commit ce8f53709bf440100cb9d31b1303291551cf517f
(drm/radeon/kms/pm: rework power management). At least, I'm able to reproduce
the symptom, which is that the machine hangs hard around the point where an
image is created (probably during the device thaw phase), on two different
boxes with r300 (the output of lspci from one of them is attached for
reference, the other one is HP nx6325).

Suspend to RAM appears to work fine at least on one of the affected boxes.

Unfortunately, the commit above changes a lot of code and it's not too easy to
figure out what's wrong with it and I didn't have the time to look more into
details of this failure. However, it looks like you use .suspend() and
..resume() callbacks as .freeze() and .thaw() which may not be 100% correct
(in fact it looks like the "legacy" PCI suspend/resume is used, which is not
recommended any more).

Thanks,
Rafael