https://bugs.freedesktop.org/show_bug.cgi?id=102800
--- Comment #1 from Alex Deucher alexdeucher@gmail.com --- (In reply to higuita from comment #0)
Finally, If i boot the system with radeon.runpm=1, it works
Let me know if you need more logs
runpm is enabled by default so specifying it shouldn't change anything. Please attach your xorg log and dmesg output.