This bug still alive within Linux version 4.10.0-19-lowlatency (booting UbuntuStudio 17.04 from USB stick).
$ egrep 'drm|radeon' /media/cyril/SanDiskBlanc/dmesg170430.log [ 7.414065] [drm] Initialized [ 7.451216] [drm] VGACON disable radeon kernel modesetting. [ 7.451282] [drm:radeon_init [radeon]] *ERROR* No UMS support in radeon module! [ 17.166670] [drm] VGACON disable radeon kernel modesetting. [ 17.166728] [drm:radeon_init [radeon]] *ERROR* No UMS support in radeon module! [ 29.316284] [drm] VGACON disable radeon kernel modesetting. [ 29.316343] [drm:radeon_init [radeon]] *ERROR* No UMS support in radeon module! $ (see apport information just before this post). Quite annoying because AMD proprietary driver unavailable for new kernels. Status moved from Expired to New. ** Changed in: xorg (Ubuntu) Status: Expired => New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1576864 Title: Unable to extend to second display To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1576864/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs