| Summary: | PowerDevil periodically pokes DPMS while the screen is off | ||
|---|---|---|---|
| Product: | [Plasma] plasmashell | Reporter: | heikki |
| Component: | Power management & brightness | Assignee: | Plasma Bugs List <plasma-bugs> |
| Status: | RESOLVED UNMAINTAINED | ||
| Severity: | normal | ||
| Priority: | NOR | ||
| Version First Reported In: | 6.3.6 | ||
| Target Milestone: | 1.0 | ||
| Platform: | Debian stable | ||
| OS: | Linux | ||
| Latest Commit: | Version Fixed In: | ||
| Sentry Crash Report: | |||
Thank you for the bug report! Debian advises users to not submit bugs upstream (https://www.debian.org/Bugs/Reporting), and Plasma 6.3.6 is no longer eligible for support or maintenance from KDE. It's possible that the issue exists only in Debian at this point. Could you report the bug to Debian using the report bug utility (https://packages.debian.org/stable/utils/reportbug)? If necessary, the maintainer of the package will forward the bug upstream. Thanks for understanding! Thanks again! |
SUMMARY PowerDevil periodically pokes DPMS while the screen is off, causing USB hub devices to briefly wake, even when no user activity occurs. This bothers me because I have connected a back light (and my mouse) to the usb hub of my monitor, so powering it on causes blips in the backlight. STEPS TO REPRODUCE 1 Login to Plasma 6 on X11 or Wayland. 2 Lock the screen with Ctrl–Alt–L. 3 Let the monitor enter DPMS-off state. 4 Wait ~25 seconds — the monitor briefly wakes (1–2 s), and the USB hub devices power on. 5 Start audio playback (e.g., Audacious); the blips stop immediately. 6 Stop audio playback; blips resume. OBSERVED RESULT DPMS briefly toggled every ~25 s when no audio is playing. USB hub devices wake during these short DPMS pulses. No logging appears in journalctl --user or via dbus-monitor. EXPECTED RESULT Once the screen is off via DPMS, it should remain off until user activity. PowerDevil should not trigger brief wake pulses that affect USB hubs. SOFTWARE/OS VERSIONS Debian Trixie Linux/KDE Plasma: 4:6.3.6 KDE Plasma Version: 4:6.3.6 ADDITIONAL INFORMATION I did see this kind of blibs on Plasma5 (Debian Bookworm), but not nearly as often. Maybe a few times in an hour. Editing ~/.config/powermanagementprofilesrc to set [AC][DimDisplay] idleTime=0 stops the blips. The blips are suppressed while audio is playing, suggesting the DPMS timer is internally inhibited by active audio streams. No D-Bus or external signals trigger these DPMS pokes; it seems to occur entirely inside PowerDevil’s timers. This happens on my BenQ PD3200U monitor Suggestions: The internal PowerDevil idle timer should not touch DPMS when the screen is already off. Consider separating “monitor off” checks from periodic timers that can wake USB devices unnecessarily.