Native Wayland integration does not inhibit screen blank on video playback

[Ppreuss98]

Affected version: 1.6.0
Restore Policy: Conservative
Idle Blanking: On

OS: CachyOS x86_64
Kernel: Linux 7.2.3-1-cachyos
Display (LG TV SSCR2): 3840x2160 @ 2x in 72", 144 Hz [External]
Desktop Environment: KDE Plasma 6.7.4
Window Manager: KWin (Wayland)
GPU: NVIDIA GeForce RTX 3080 Ti [Discrete]

Steps:

• Open config app
• Set blank timeout to low value (5)
• Set desktop integration to Automatic or Wayland
• Start video playback
• Stop inputs (mouse/keyboard)
• Screen goes blank after timeout
• Stop video playback
• Switch desktop integration to swayidle
• Start video playback
• Stop inputs (mouse/keyboard)
• Screen does not go blank after timeout

[Staphylococcus]

Thanks for the report! Current behavior is intentional, as part of the OLED burn-in prevention suite of measures (think leaving a video game on and walking away from the screen), but I can see how its aggressive nature can be counterintuitive and not desirable in every situation. I'll be making it configurable so you can choose a more passive behavior.

[Staphylococcus]

@Ppreuss98 please check the latest v1.7.0 release, and tell me if the app is working better for you

[Ppreuss98]

Hi @Staphylococcus, it is still not working. I am using Vivaldi with a YouTube video to test the behavior - maybe this info will help. I also tried wayland-pipewire-idle-inhibit, but it didn't change the behavior. Let me know if I can assist somehow. Also, oddly, the screen goes blank when playing back video in Haruna Video Player and in Proton Games, when no input is given (swayidle and wayland native).

Edit: Screen does not blank with mpv video player on swayidle

[Staphylococcus]

Thanks, this already helps a lot. This is a consequence of me doing this change a bit prematurely without correctly modeling the backend to support this. Let me take another stab at it and I'll create a pre-release for testing.

[Staphylococcus]

@Ppreuss98 v1.8.0-beta.1 is ready for testing. This reworks app-inhibition handling and adds KWin's native Wayland inhibition alongside PowerDevil.

Could you retry your Vivaldi/YouTube, Haruna and Proton cases?

1. In Settings → Updates, select the prerelease channel and install 1.8.0-beta.1.
2. If Legacy desktop integration appears, choose Use automatic. Enable Idle blanking and Allow apps to prevent idle blanking, with a short timeout.
3. Start playback, leave input idle, and check whether the screen stays on. Then stop playback and check whether idle blanking resumes. If possible, also try playback already running when LG Buddy starts; mpv is a useful comparison.

Please let us know which cases work and which still blank. For any remaining problem, refresh Diagnostics from the app menu while it is happening and share the report, along with your current Plasma version. Review the report's local addresses before posting. Thanks for helping test this!

[Ppreuss98]

@Staphylococcus Here are my findings:

• Screen does blank when no inhibitor is present (correct)
• Screen does not blank while a Proton Game is open (correct)
• Screen does not blank while a YT Video plays on Vivaldi (correct)
• Screen does not blank while Haruna Media Player plays a video (correct)
• Screen does not blank while Haruna Media Player plays a video and LG_Buddy_lifecycle.service was restarted after playback started (correct)
• Screen does blank while MPV plays a video (incorrect)

Diagnostics from mpv blanking:
diag.txt

[Staphylococcus]

@Ppreuss98 Thanks for testing those cases. 1.8.0-beta.2 improves diagnostics so we can see KWin's current availability and inhibition state directly. The mpv cause is still under investigation.

Please update through Settings → Updates → Prerelease, then leave a video playing in mpv and use Diagnostics → Refresh → Save. Attach that fresh report here; there is no need to wait for the screen to blank before collecting it. If it does blank, wake it and leave the video playing while collecting the report.

That should tell us whether the KWin source is present and whether it sees mpv's inhibitor, with recent logs alongside the snapshot. Thanks!

[Ppreuss98]

@Staphylococcus Here are the diagnostics:
lg-buddy-diagnostics.txt

[Staphylococcus]

@Ppreuss98 Thanks, it's a bit of a mystery. Could you run:

cat "${XDG_STATE_HOME:-$HOME/.local/state}/lg-buddy/kwin/setup.log"
journalctl --user -b -u LG_Buddy_kwin.service --no-pager -n 80
lg-buddy kwin-bridge info

And paste the outputs?

[Ppreuss98]

@Staphylococcus
Output:

cat /home/xyz/.local/state/lg-buddy/kwin/setup.log
 journalctl --user -b -u LG_Buddy_kwin.service --no-pager -n 80
 lg-buddy kwin-bridge info

Sep 15 10:25:38 cachyos-x8664 systemd[970]: Starting LG Buddy optional KWin integration setup...
Sep 15 10:25:38 cachyos-x8664 systemd[970]: Finished LG Buddy optional KWin integration setup.
6.7.5   6.11.2  /usr/lib64/qt6/plugins  :1.10

The setup.log file is empty but present for whatever reason

[Ppreuss98]

@Staphylococcus
I have found some hints on this behavior:

• https://mpv.io/manual/master/#options-stop-screensaver
• https://www.linux.org/threads/solved-issue-screen-blacking-out-with-mpv-only.41614/

I presume this is then an "user error"? MPV seems to not work well with wayland inhibitors.
For the time being I've changed to another player for my use case. All other issues are solved, so this bug could be deprioritized.

[Staphylococcus]

@Ppreuss98 apologies, I forgot to loop you in on the recent developments. The most recent released version contains what I think should address your MPV issue at a deeper level than my previous attempts. I'm suspecting that the app was not listening to the way MPV sets inhibition, so LG Buddy now reports in settings if any component is not set up correctly, and offers to complete setup. Check if your setup needs to be fixed via the settings tab.

[Ppreuss98]

@Staphylococcus I tested the behavior with 1.8.0 and everything is working correctly. Thank you very much!

[Staphylococcus]

Thanks for the confirmation and for all the help chasing this one down @Ppreuss98 ! Closing this one now, but feel free to reopen, or open a new one if anything else comes along.