Hibernate fails with open source radeon driver

Question

I have set up hibernate properly and it worked on Catalyst.
Today I switched to the open source driver and I can't put my computer in hibernate or hybrid sleep mode. When I try, both of my monitors turn off then immediately turn back on with a completely blank picture. They both report that they are getting the correct mode for them. At this point my HDD led is not blinking (I'm pretty sure the HDD itself has stopped, didn't check), and the reset button is ineffective. If I forcefully power of the PC and turn it back on it boots as if nothing has happened.
I tried linux-ice and uswsusp but neither solved my problem.
Further debugging shows that this is due to KMS (booting with nomodeset lets me hibernate successfully but I'd like to run X). Using the kernel documentation's debug procedures (https://www.kernel.org/doc/Documentatio … ugging.txt) I found that it happens when the kernel suspends devices. I can't really provide much more info unless you guys know how to squeeze it out of the kernel.
It's worth mentioning my GPU is an HD7970 (I can list other things if needed), and that the driver works perfectly fine otherwise. I do recall that hibernating worked at one point but I can't remember when it was broken as I first discovered the bug a few months ago after switching back from catalyst.
I found some guy on the Gentoo forums with the same issue (http://forums.gentoo.org/viewtopic-p-7642484.html) so it might be an upstream bug in the driver. If anyone could shed some light or tell me where to report this bug in particular (kernel ? freedesktop.org ?) I'd be grateful.
Thanks in advance.
Last edited by Streetwalker (2014-12-23 19:56:07)

Answer 1

Alright I found the culprit. Adding radeon.dpm=0 to the kernel command line lets me hibernate on the current kernel. I lose power management but it's fine for now, will definitely check things out in the source when I have time.