Continued the battle for additional 1.5 hours. I verified that both displays work fine when connected directly to the laptop (1 DP) without the HP ultraslim docking station (2 DPs) between.
After powering off the docking station and rebooting the system for Nth time, I finally got the pictures back. It's worth noting that the password prompt for disk decryption was not shown on external displays, nor the booting sequence. X11 login prompt was the first image. It seems this was somehow affected by the docking station. Resolved for now, but the ultimate cause stays unknown. -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1712005 Title: External displays blank, kernel errors from i915/drm driver To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1712005/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp