Update: I've not hit this bug after 5 days now, and I need to restart to apply security updates.
To recap, the fix was to add the following to /etc/rc.local : echo auto > /sys/class/drm/card0/device/power_profile -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1442311 Title: Ubuntu 14.04 blank screen after wakeup from sleep To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1442311/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs