Comment 48 for bug 471872

@duncand: NickA comment #23 gives the workaround. To sum it up, you need to create a file (/etc/modprobe.d/radeon-kms.conf) with a single command in it. This will tell your video driver not to load the kms module (kms stands for kernel messaging service). This fixes the suspend problem but it does degrade the video quality. I think the trade-off is worth it to be able to close the lid to my laptop and have it go into suspend, then open the lid to my laptop and have it come back perfectly every time.

OK, now here's how to implement the fix.

    $ echo "echo options radeon modeset=0 > /etc/modprobe.d/radeon-kms.conf" > suspend.sh
    $ chmod ugo+x suspend.sh
    $ sudo ./suspend.sh

The first command creates a shell script called "suspend.sh" that will create the file "/etc/modprobe.d/radeon-kms.conf" with the command "echo options radeon modeset=0" in it.

The second command make "suspend.sh" executable.

The third command executes "suspend.sh" as the superuser. You need to be the superuser to edit files in the "/etc/modprobe.d/" directory.

That's it! You should now shutdown and restart your laptop and you will be able to suspend without any problems. As I said, the video will look pretty bad and your desktop icons will be ugly but I've found the system to be very usable this way. If you ever want to go back, just delete "/etc/modprobe.d/radeon-kms.conf" as the superuser and your system is back the way it started.

HTH,
Andy