Bug 427973

Summary:	Multi-screen / wayland: Only mouse pointer shown after standby
Product:	[Plasma] kwin	Reporter:	Roman Zimmermann <torotil>
Component:	wayland-generic	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	eyadquraan
Priority:	NOR
Version First Reported In:	5.20.0
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Roman Zimmermann 2020-10-19 11:47:54 UTC

On wayland with an external monitor connected the screen doesn’t return after the monitors are sent to standby.


STEPS TO REPRODUCE
1. Have multiple monitors connected
2. Idle long enough for the screen-lock to appear and the monitors to go into standby
3. move the mouse cursor / switch to terminal and back

OBSERVED RESULT

The monitors stay black only the mouse cursor is drawn on the external monitors. It’s not possible to move it to the other moniter. I’ve also tried unplugging the external monitor. Then the black screen and cursor move the laptop’s monitor.

EXPECTED RESULT
Lock screen appears and I can unlock the desktop.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Gentoo
KDE Plasma Version: 5.20.0
KDE Frameworks Version: 5.74.0
Qt Version: 5.15.1

ADDITIONAL INFORMATION
Before the upgrade to 5.20.0 I’ve used 5.19.5 which had the same issue, but the lock-screen would reappear most of the times after switching to another VT and back again.

Comment 1 eyadquraan 2020-10-25 17:16:37 UTC

I seem to have the same problem as well. The only thing I can do is hit the reset button on my PC. For now, I just disabled locking. Let me know how to get debugging info if it's needed. I use two HP screens (25ES, 22cwa) if that helps.

Plasma 5.20 of course

OS: OpenSuse Tumbleweed
CPU: Ryzen 2600X
GPU: Radeon RX 5600XT

Comment 2 eyadquraan 2020-10-26 02:08:37 UTC

I think this bug may be related to LatteDock (it says something about Wayland in the backtrace). I disabled screen locking and let my pc sit for 20 minutes. I came back to three separate crashes that happened around the same time. Here are those backtraces:

kactivitymanagerd - https://pastebin.com/Gx9Pf1Gp
kde connect dameon - https://pastebin.com/W1HfvKN9
latte dock - https://pastebin.com/aF9UhQuS

Comment 3 Vlad Zahorodnii 2020-10-26 09:00:44 UTC

This bug should be fixed after updating Qt to 5.15.2 and rebuilding kwayland-server against it.

*** This bug has been marked as a duplicate of bug 426293 ***

Comment 4 eyadquraan 2020-10-27 00:13:52 UTC

Thank you, what I tried did not work anyways.