OK, so, I've learned more about this. If I wait for like 10-15 seconds after waking the laptop and type ctrl- alt-f1, then after a long delay after that the screen will switch to the GNOME login screen, and then if I select my account and type my password, I am brought back to my previous session. But, there's something weird about the state of things at that point. E.g., if I then put the laptop to sleep and wake it back up again, the lock screen for my session appears, but it won't accept any keyboard or mouse input. To get back into my session I have to do the ctrl-alt-f1 trick again.
If I open the laptop while docked, wait for the built-in screen to activate such that all three monitors are active, then undock and suspend the laptop before gdm3 finishes reconfiguring so that only the laptop screen is active, then I'm in the same boat as the original bug report when I wake up the laptop, i.e., the screen remains black no matter how long I wait, but if I wait a while after waking and then type ctrl-alt-f1 I can proceed as in the previous paragraph. If I open the laptop while docked, wait for the built-in screen to activate such that all three monitors are active, undock, wait for gdm3 to finish reconfiguring so that only the laptop screen is active, _then_ suspend the laptop, then when I wake the laptop back up the screen does come on. In short, it appears that the problem is related to suspending the computer when it is in the middle of reconfiguring what its active screens are. It doesn't finish or restart that configuration when it wakes up, so it remains in a weird, messed-up state. At least, that's my best guess, given the data I've collected. -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gdm3 in Ubuntu. https://bugs.launchpad.net/bugs/1802574 Title: laptop screen never comes on after undock / sleep / open of laptop To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/1802574/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
