Public bug reported: I have a Lenovo X1 Carbon with an external screen connected to a Mini DP to VGA adapter. External screen works fine until the display goes to sleep for inactivity (just the display goes to sleep, not the laptop). When I return to the laptop, the built in screen wakes but the external screen does not. The screen is still detected, xrandr displays the resolution and I can move the cursor to the external display but the display remains off. I have tried cycling with Fn+F7 and also tried Ctrl+Alt+F1 then Ctrl+Alt+F7. The only way to get the external display back on is by disconnecting the adapter from the laptops DP port and reconnecting.
dmesg produces: drm:intel_dp_complete_link_train] *ERROR* failed to train DP, aborting Running Description: Ubuntu 13.04 Release: 13.04 kernel 3.8.0-23-generic xserver-xorg-video-intel: Installed: 2:2.21.6-0ubuntu4 As a workaround I have disabled the monitor from sleeping in System Settings->Brightness & Lock-> Turn Screen off when inactive for ** Affects: xserver-xorg-video-intel (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1189639 Title: External Screen doesn't wake up from sleep To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/1189639/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs