I am also affected by this bug after upgrading to Xenial and trying to use radeon KMS. My system will only boot with `nomodeset` or `radeon.modeset=0`. Futhermore, attempting `sudo modprobe radeon modeset=1` after booting with `nomodeset` results in the same error state: screen goes blank, monitor's "No signal detected" message appears. Sometimes the machine reboots, but not always.
I have a Radeon HD5770 card. I will try to attach logs via apport -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1568211 Title: no UMS support in radeon module To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1568211/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
