Bug 437471 - Under certain circumstances, cannot unlock screen after undocking while laptop screen was off
Summary: Under certain circumstances, cannot unlock screen after undocking while lapto...
Status: RESOLVED FIXED
Alias: None
Product: kscreenlocker
Classification: Plasma
Component: general (show other bugs)
Version: 5.24.2
Platform: Arch Linux Linux
: VHI critical
Target Milestone: ---
Assignee: Plasma Bugs List
URL:
Keywords:
: 450542 (view as bug list)
Depends on:
Blocks:
 
Reported: 2021-05-21 19:37 UTC by Emre
Modified: 2023-02-28 19:47 UTC (History)
6 users (show)

See Also:
Latest Commit:
Version Fixed In: 5.27.1
Sentry Crash Report:


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Description Emre 2021-05-21 19:37:55 UTC
SUMMARY
When undocking from thunderbolt docking station with laptop lid closed, and opening the lid, the screen is on, mouse pointer is visible. Screen locker is not visible and desktop cannot be accessed as password cannot be entered.

Going to other TTY console, logging in and killing kscreenlocker_greeter brings the screenlock window back and then the desktop can then be unlocked. 

STEPS TO REPRODUCE
1. Dock your laptop and close the laptop lid (settings to not standby when lid closed). Work with your external monitors.
2. Unplug your thunderbolt docking cable while laptop lid is closed. 
3. Open the lid of your laptop, see that mouse pointer is visible, but no screenlocker window to enter your password.

OBSERVED RESULT
screenlocker window to enter your password is not visible (probably it still thinks its displaying on external monitors which no longer exist). You can't enter your password and you can't unlock, hence you can't access your desktop.

EXPECTED RESULT
screenlocker is presented and I can enter my password to access my desktop

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 5.21.5 / 5.82.0 (latest on Arch as of 20/05/2021)
KDE Plasma Version:  5.21.5 / 5.82.0
KDE Frameworks Version:  5.21.5 / 5.82.0
Qt Version:  5.15.2

ADDITIONAL INFORMATION
Comment 1 Nate Graham 2021-06-21 23:08:43 UTC

*** This bug has been marked as a duplicate of bug 370676 ***
Comment 2 Emre 2022-03-04 06:56:51 UTC
I dont think this is a duplicate of the other case. This is happening in Wayland.
Maybe a bit more precision to help debug it.  I'm now using KDE 5.24.2. 

In my scenario, laptop is docked with Thunderbolt port, using two external screens, laptop screen is off (closed or open, but off).
I lock my screen.  I can unlock it fine as long as I dont undock.

But if I undock it while screen was locked, the laptop screen turns on as expected, and displays the wallpaper. But the lockscreen password entry box is not visible. Moving mouse around, trying to go to TTY and back, does not help, no password entry box. 
Entering password manually does not make any difference neither. 
So it seems the lockscreen password entry box is stuck in a monitor/screen which no longer exists as the laptop is undocked, and it's not moved to the active screen/monitor.

This is a dealbreaker case for many laptop users.
Comment 3 Emre 2022-03-04 07:01:53 UTC
This bug now forces me to remember to unlock first, then undock my laptop. In that case the laptop monitor gets activated and application windows move to the laptop screen, so workflow is not broken.
If I happen to forget to unlock, ie need to undock & take my laptop urgently, then I can't unlock anymore... Need to force power off the laptop and maybe lose data...
Comment 4 Nate Graham 2022-11-04 20:16:30 UTC
Would be automatically fixed by Bug 409226 plus the upcoming multi-screen overhaul in Plasma 5.27.
Comment 5 Nate Graham 2022-11-04 21:51:44 UTC
Maybe we're hitting Bug 374890?
Comment 6 Simon B 2022-12-26 13:54:42 UTC
*** Bug 450542 has been marked as a duplicate of this bug. ***
Comment 7 Simon B 2023-02-28 16:52:54 UTC
I say this tentatively, as this bug has plagued me for a long time, but...
plasma 5.27.1 seems to fix this for me. Can anyone else confirm? wake-up time is a little long but after about 15s the laptop screen comes alive, which it never did before
Comment 8 Nate Graham 2023-02-28 19:47:07 UTC
Just gave this a try with Plasma 5.27.2 and I also can't reproduce the issue. When I unplug the docking station that the only enabled monitors are attached to and open the laptop lid, I see the lock screen. Hooray! Let's call it fixed.