You have been subscribed to a public bug: 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: linux (Ubuntu) Importance: Low Status: Incomplete ** Tags: resume -- [dp] External Screen doesn't wake up from sleep https://bugs.launchpad.net/bugs/1189639 You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp