Bug 495456

Summary:	Plasma (Wayland) session screen goes black after login (AMD GPU) until switching TTYs with DDC active
Product:	[Plasma] Powerdevil	Reporter:	Johnny <jgb.mcdonald>
Component:	general	Assignee:	Plasma Bugs List <plasma-bugs>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	jpetso, kde, natalie_clarius, nate
Priority:	NOR	Keywords:	regression
Version:	6.2.2
Target Milestone:	---
Platform:	openSUSE
OS:	Linux
See Also:	https://bugs.kde.org/show_bug.cgi?id=494899
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	Screenshot showing one device under display & monitor Bootlog from today

Description Johnny 2024-10-28 01:47:31 UTC

SUMMARY
After I login to a wayland plasma session with sddm the desktop will appear temporarily, then after a few seconds the screen will go completely black (no cursor or anything else) and remain black.

STEPS TO REPRODUCE
1. Select Plasma Wayland Session from SDDM
2. Enter log in password and hit enter

OBSERVED RESULT
Plasma desktop appears briefly (several seconds) and then the screen goes completely black and stays black.

EXPECTED RESULT
Plasma desktop appears and remains visible.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: openSUSE Tumbleweed 20241025
KDE Plasma Version: 6.2.2
KDE Frameworks Version: 6.7.0
Qt Version: 6.8.0

ADDITIONAL INFORMATION
The monitor appears to still receive signal. Additionally, I can switch to a TTY and then back to the plasma session and then the desktop will sometimes reappear and then stay visible.
If I kill the session with ctrl+alt+backspace x2 I can switch to an X11 plasma session which works fine.

This occurs after every wayland plasma login with OpenSuse Tumbleweed and persists even after a full reinstall of the OS.
(It occurs on Fedora KDE (wayland) also).
Other DE’s do not cause the issue to arise (I have installed alternative DEs to check whether it was an OpenSuse and/or Fedora issue - for instance Cinnamon Wayland on Fedora works fine).

I have already posted this issue in KDE discussion forum however no one has been able to assist in resolving the issue.
I have never filed a bug report before and am unsure which logs/additional information I should provide with this report nor how to do the debugging process (despite reading the articles on this).

Comment 1 Nate Graham 2024-10-28 16:05:24 UTC

Do you have extra empty entries in the "Device:" dropdown menu in System Settings > Display & monitor? If so, I think this is very likely Bug 493810.

Comment 2 Johnny 2024-10-28 18:04:50 UTC

(In reply to Nate Graham from comment #1)
> Do you have extra empty entries in the "Device:" dropdown menu in System
> Settings > Display & monitor? If so, I think this is very likely Bug 493810.

No, only one device appears on that page. 
I was able to quickly take a screenshot of this before the screen went black and can upload it if it would be useful.

Comment 3 Nate Graham 2024-10-28 20:18:50 UTC

Sure, that might be useful!

Comment 4 Johnny 2024-10-29 01:59:14 UTC

Created attachment 175319 [details]
Screenshot showing one device under display & monitor

Comment 5 Johnny 2024-10-29 02:32:42 UTC

Created attachment 175320 [details]
Bootlog from today

Bootlog from today; logging in to plasma wayland session (with black screen bug occurring), then into X11 session.

Comment 6 Johnny 2024-10-29 02:39:30 UTC

(In reply to Nate Graham from comment #3)
> Sure, that might be useful!

I have uploaded the screenshot as well as a bootlog from journalctl in case it can help.

Comment 7 Johnny 2024-10-30 05:22:24 UTC

I have resolved this issue.
It appears to be an issue with powerdevil DDC/CI and my monitor.
Disabling DDC/CI in the powerdevil service has fixed it.

Comment 8 Nate Graham 2024-10-30 14:21:50 UTC

Thanks for the info; that's a useful workaround to know. which shows us it's a Powerdevil issue. Moving over there.

Comment 9 Nate Graham 2024-11-11 22:25:21 UTC


*** This bug has been marked as a duplicate of bug 494899 ***