https://bugs.freedesktop.org/show_bug.cgi?id=29026
--- Comment #5 from Rafał Miłecki zajec5@gmail.com 2010-07-12 23:03:56 PDT --- (In reply to comment #3)
same problem for me, with last drm-radeon-testing kernel on a rv620 (dell studio 15 laptop).
I'm using archlinux, with last mesa-git, ati-git,libdrm-git.
What about pm-utils? Do you use it? If so, try version 1.3.0 which recognizes KMS.