In the Settings Power Management dialogue I set Screen Energy saving to Switch off after 30 mins, which it does, but then immediately comes on again. This “off then on” then repeats every half hour. Any ideas on what might be forcing my monitor to immediately reawaken?
Cheers
Fred
Desktop, HDMI Montior, LEAP 15.1, KDE Plasma 5.12.18
I have no idea. But I would guess that something happens when switching it off that tells the system it is time to wake up.
Many years ago on older hardware, I had Windows 95. And it worked pretty well. Then I upgraded to Windows 98 and had the same problem. After the system was idle for a while, the monitor would turn off. This was immediately followed by a burst of activity that turned the monitor on again. I never did find a solution, but since I mainly used linux, I could live with it.
What you are seeing is probably a bug of some sort. But it doesn’t happen here, so presumably it is specific to your hardware.
Hmm, I was afraid there might be no obvious culprit. It’s AMD-based kit, Ryzen 5 Radeon RX 580. I’ve had a number of tricky issues with this kit - occasional total freeze - but with each new kernel release it gets a bit better. 
Maybe try a newer kernel from the kernel-stable repo
http://download.opensuse.org/repositories/Kernel:/stable/standard/
Can’t hurt - will give it a try. Thanks.
Same here with Leap 15.2 – Plasma version 5.18.5 – KDE Frameworks: 5.71.0 – AMD Ryzen 5 3400G with Radeon Vega Graphics – HDMI Monitor.
“xset dpms force standby / suspend / off” all turn the Display off perfectly but, after 15 seconds the Display turns back on again …
And, the Display Manager SDDM works absolutely perfectly – it even drops the Display down into a “deep sleep” mode after a while and, it stays in Energy saving mode – no “waking up” …
[HR][/HR]Fridays for future
I’m sorry, I didn’t understand this paragraph, are you saying you found something that works?
Oh, and just for general information, I had occasion to swap out my Radeon RX580 for an Nvidia GEFORCE GTX1050Ti and sleep works perfectly with that. Definitely a video card issue.
I have the same identical issue with Suse 15.2. with a Radeon RX 550 card.
This is a new card that replaced an old Nvidia card.
The Nvidia did NOT have this issue…
The ‘turn on’ is supposed to ONLY happen on a mouse or keyboard interrupt.
However, it looks like something else is waking up the display…
Richard Rosa
When X11 fires up, it needs a Display Manager which, in the case of KDE, is usually the “Simple Desktop Display Manager” – SDDM.
And, guess what, the thing which fires up KDE after the system boot has completed, understands Monitor Energy Saving perfectly …
Ah, right, I understand now. Yes, that’s a little odd, something further down the KDE user session must be breaking it.
I may have found the issue:
Sep 05 11:55:32 ... plasma_session[3179]: org.kde.plasma.session: Starting autostart service "/etc/xdg/autostart/powerdevil.desktop" ("/usr/lib64/libexec/org_kde_powerdevil")
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: No outputs have backlight property
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: Xrandr not supported, trying ddc, helper
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: [DDCutilBrightness] compiled without DDC/CI support
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: Falling back to helper to get brightness
Sep 05 11:55:32 ... backlighthelper[3264]: powerdevil: no kernel backlight interface found
Sep 05 11:55:32 ... dbus-daemon[1132]: [system] Successfully activated service 'org.kde.powerdevil.backlighthelper'
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: org.kde.powerdevil.backlighthelper.brightness failed
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: ""
Sep 05 11:55:32 ... dbus-daemon[1132]: [system] Rejected send message, 2 matched rules; type="method_call", sender=":1.39" (uid=1000 pid=3227 comm="/usr/lib64/libexec/org_kde_powerdevil ") interface="org.freedesktop.login1.Manager" member="CanSuspendThenHibernate" error name="(unset)" requested_reply="0" destination="org.freedesktop.login1" >
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: Backend ready, KDE Power Management system initialized
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: Got a valid offer for "DPMSControl"
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: Can't contact ck
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: Currently using activity "13127a49-0179-44e1-8c6d-1e7d579e46ce"
Sep 05 11:55:32 ... dbus-daemon[3033]: [session uid=1000 pid=3033] Activating service name='org.kde.KScreen' requested by ':1.24' (uid=1000 pid=3227 comm="/usr/lib64/libexec/org_kde_powerdevil ")
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: () ()
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: () ()
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: No batteries found, loading AC
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: Activity is not forcing a profile
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: The profile "AC" tried to activate "DimDisplay" a non-existent action. This is usually due to an installation problem, a configuration problem, or because the action is not supported
Sep 05 11:55:32 ... org_kde_powerdevil[3227]: powerdevil: Handle button events action could not check for screen configuration
Sep 05 11:55:32 ... kded5[3129]: Imported file "/usr/share/khotkeys/konqueror_gestures_kde321.khotkeys"
Sep 05 11:55:32 ... kded5[3129]: Imported file "/usr/share/khotkeys/kde32b1.khotkeys"
Sep 05 11:55:32 ... kded5[3129]: Imported file "/usr/share/khotkeys/konsole.khotkeys"
Sep 05 11:55:32 ... kded5[3129]: Imported file "/usr/share/khotkeys/defaults.khotkeys"
Sep 05 11:55:32 ... dbus-daemon[3033]: [session uid=1000 pid=3033] Successfully activated service 'org.kde.KScreen'
Sep 05 11:55:32 ... kscreen_backend_launcher[3269]: kscreen.xrandr: Connected output 83 to CRTC 79
Sep 05 11:55:32 ... kscreen_backend_launcher[3269]: kscreen.xcb.helper: Detected XRandR 1.6
Sep 05 11:55:32 ... kscreen_backend_launcher[3269]: kscreen.xcb.helper: Event Base: 89
Sep 05 11:55:32 ... kscreen_backend_launcher[3269]: kscreen.xcb.helper: Event Error: 147
Also this entry when the KDE Power Saving is being setup:
Sep 05 18:27:08 ... systemsettings5[21891]: Couldn't load plugin "kcms/kcm_powerdevilprofilesconfig" : "Die dynamische Bibliothek konnte nicht gefunden werden." -- falling back to old-style loading from desktop file
Which is not exactly correct because the “powerdevil5” package contains:
/usr/lib64/qt5/plugins/kcm_powerdevilprofilesconfig.so
As well as some other much needed plugins, such as:
/usr/share/dbus-1/system-services/org.kde.powerdevil.backlighthelper.service
[HR][/HR]I’ve raised Bug Report #1176199 – “PowerDevil finds neither the KCM plugin nor the D-Bus Backlight helper”
The issue seems to have disappeared …
Add virtual output device for simultaneous output on all local sound cards
Whether or not there was also a patch which influenced the behaviour, is something I can neither confirm nor, deny …
I have this issue since I got my new EIZO monitor. With the previous HP monitor, the screen turns off and stays off; I verified that by simply exchaning the monitors again.
When I use xset dpms force off, the monitor turns off, after 5 seconds pops up a message that it goes into power-save mode, and 5 seconds after switching off, comes back on again.
This does not happen in the dually installed Windows 10, and neither on the login screen of KDE: There, the monitor turns off and also stays off until the mouse is moved or a key is pressed.
So it seems to be an issue in KDE which occurs for some monitors, not for all.