@Mathew Hodson. I removed the amdgpu blacklist entry I had manually added and used the "Additional Drivers" tab of Software and Updates to switch to the Open Source drivers.
This resulted in a fallback Unity desktop without GPU acceleration ( glxinfo reported gallium using llvmpipe, which is mesa's software implementation of OpenGL as far as I know ). It was usable but slightly laggy. This process had left traces of fglrx-core and fglrx in the dpkg database. When I purged these, and rebooted, LightDM worked, but Unity hung on at ( first flickering, but eventually stable ) the desktop background, with no other screen artifacts. Manually installing the fglrx-updates set of packages from wily-proposed then gave me the full binary driver accelerated desktop correctly without the need to blacklist anything. Subsequently switching to the open source drivers still fails to give me GPU acceleration for X ( llvmpipe again ). So something does not appear to be set or removed properly in the process of going from Proprietary to Open Source drivers. I'll see if I can find out what. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1493888 Title: FGLRX incompatible with gcc 5 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-release-notes/+bug/1493888/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs