https://bugs.freedesktop.org/show_bug.cgi?id=73530
--- Comment #14 from Alex Deucher agd5f@yahoo.com --- (In reply to comment #9)
Applying your patch to disable ss to Linux 3.13-rc8 worked. The monitor displays now something even with KMS. Thanks!
It could still be that something else fixed it in Linux 3.13-rc8 which was not yet in 3.12.6. I’ll post the logs so you can decide.
Can you test 3.13-rc8 without the ss-patch to confirm what fixed it?