Bug 477323 - Samsung Odyssey G5 (LC27G5xT) display does not initialize properly after logging in
Summary: Samsung Odyssey G5 (LC27G5xT) display does not initialize properly after logg...
Status: RESOLVED WORKSFORME
Alias: None
Product: kwin
Classification: Plasma
Component: multi-screen (show other bugs)
Version: 5.27.9
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords: wayland-only
Depends on:
Blocks:
 
Reported: 2023-11-21 12:15 UTC by Fenic
Modified: 2024-04-30 18:54 UTC (History)
2 users (show)

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


Attachments
Journal output when display is working (13.18 KB, text/plain)
2023-12-05 16:10 UTC, Fenic
Details
Journal output when display is not working (10.77 KB, text/plain)
2023-12-05 16:11 UTC, Fenic
Details
drm_info when display is working (116.60 KB, text/plain)
2023-12-05 16:11 UTC, Fenic
Details
drm_info when display is not working (116.60 KB, text/plain)
2023-12-05 16:11 UTC, Fenic
Details

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Description Fenic 2023-11-21 12:15:19 UTC
SUMMARY
When booting my system with NVIDIA's DRM enabled, my Samsung Odyssey display only shows a black screen after logging in.

Having the screen off while I boot and log in, and then turning the display on causes no significant issues and allows for the display to work like normal.

STEPS TO REPRODUCE
1. Boot your system with a Samsung Odyssey G5 display connected
2. Log in to KDE
3. Observe that the display does not show a visual output

OBSERVED RESULT
The display is still recognized by Plasma as a display, and windows can still be moved to and from the display.

Disabling or turning the display off freezes Plasma. I have experienced that the system unfreezes itself after a while, and that enabling or turning the display back on similarly freezes Plasma.

EXPECTED RESULT
The display having a visual output without needing to have the display off during boot and login.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma:  6.6.2-zen1-1-zen 
(available in About System)
KDE Plasma Version: 5.27.9
KDE Frameworks Version: 5.112.0
Qt Version: 5.15.11

ADDITIONAL INFORMATION
I'm using SDDM in Wayland mode with kwin_wayland. I'm also using the Wayland version of Plasma, I haven't checked if the issue persists when using X11.
Comment 1 Nate Graham 2023-11-30 22:09:37 UTC
Is the screen working properly at the SDDM login screen, or is it broken there too?
Comment 2 Fenic 2023-12-04 20:58:35 UTC
(In reply to Nate Graham from comment #1)
> Is the screen working properly at the SDDM login screen, or is it broken
> there too?

The screen is functional on SDDM. I've tested a bit, and SDDM seems to be the last point where both monitors work correctly. If you turn the monitor off at that point and log in, the monitor works correctly  after logging in if it's turned back on
Comment 3 Nate Graham 2023-12-04 21:30:30 UTC
Fascinating.
Comment 4 Zamundaaa 2023-12-05 11:26:02 UTC
Please attach the output of
> journalctl --user-unit plasma-kwin_wayland --boot 0
and
> drm_info

once for when the display works, and once for a boot where it doesn't work.
Comment 5 Fenic 2023-12-05 16:10:40 UTC
Created attachment 163907 [details]
Journal output when display is working
Comment 6 Fenic 2023-12-05 16:11:06 UTC
Created attachment 163908 [details]
Journal output when display is not working
Comment 7 Fenic 2023-12-05 16:11:30 UTC
Created attachment 163909 [details]
drm_info when display is working
Comment 8 Fenic 2023-12-05 16:11:50 UTC
Created attachment 163910 [details]
drm_info when display is not working
Comment 9 Fenic 2023-12-05 16:12:32 UTC
(In reply to Fenic from comment #8)
> Created attachment 163910 [details]
> drm_info when display is not working

Added attachments as requested
Comment 10 Fenic 2023-12-13 13:53:04 UTC
I've identified that this issue only seems to be occurring when running SDDM in Wayland mode. When I removed the config file for running SDDM under Wayland the issue resolved itself when I rebooted
Comment 11 Zamundaaa 2023-12-13 16:41:34 UTC
That's interesting. The logs don't show any difference in hardware setup or relevant warnings, but there definitely would be one with Xorg -> Wayland.
So this might be caused by the handoff between the two systems somehow going wrong, KWin not doing a modeset when the NVidia driver expects it or something like that. Does auto login to the Wayland session work?
Comment 12 Fenic 2023-12-13 17:45:07 UTC
(In reply to Zamundaaa from comment #11)
> That's interesting. The logs don't show any difference in hardware setup or
> relevant warnings, but there definitely would be one with Xorg -> Wayland.
> So this might be caused by the handoff between the two systems somehow going
> wrong, KWin not doing a modeset when the NVidia driver expects it or
> something like that. Does auto login to the Wayland session work?

Checked autologin. It seems to work both with SDDM in xorg and Wayland mode, so I'm guessing your theory about handoff being correct
Comment 13 Bug Janitor Service 2023-12-28 03:46:19 UTC
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!
Comment 14 Zamundaaa 2024-04-24 16:45:33 UTC
Does this still happen in Plasma 6 and with the latest NVidia drivers?
Comment 15 Fenic 2024-04-30 18:30:13 UTC
I haven't experienced the issue since Plasma 6. I was using NixOS briefly where the issue didn't occur, and then later returned to Arch and haven't experienced it since. The only difference I can remember between my current system and my old configuration was me using nvidia_drm.fbdev=1 until it was noticed it had issues. I'll re-enable this and see if I can recreate the issue.
Comment 16 Fenic 2024-04-30 18:54:52 UTC
I'm unable to recreate the issue, so I'm guessing it was either caused by some other config on my system I can't remember or didn't know of, or some weird NVIDIA bug that's been fixed. I'll mark this as WORKSFORME, since the issue seems to have disappeared.