I've had good enough experiences with mainline 4.8.15 at this point that I would consider this bug fixed in linux 4.8.x; it's still not perfect (have to typically play around with xrandr and maybe undock/dock), but external 4k DP monitor via a ThinkPad dock works fairly reliably now.
OTOH I was unable to get any DP video output at all with mainline Linux 4.9... -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1597267 Title: ThinkPad X260 connecting external DisplayPort hangs system To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1597267/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
