I was able to test with the latest 4.3 rc3 kernel. The output of xrandr is no different to that above and neither lxrandr nor arandr was able to detect an external screen as they usually are when I plug them in on the VGA port.
** Changed in: linux (Ubuntu) Status: Incomplete => Confirmed ** Tags added: kernel-bug-exists-upstream-4.3-rc3 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1292036 Title: Displayport on Thinkpad T420s is not usable To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1292036/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs