Bug 504529

Does the issue still happen with only one monitor connected?

Updating the status pending a response from the reporter, thanks!

Tried it: It happens with one monitor and also two monitors connected. Only X11 wakes up the screens.

Thanks - one other question, if you:

1. Save your work and exit any programs you're using to work (in case testing this makes it hard to get back to your desktop)
2. Head to System Settings > Power Management
3. Set the screen to turn off automatically, before the sleep timer is triggered (like in 1 minute)
4. Let the screen turn off, with the device still on, and wait a couple minutes

Does the monitor come back on successfully and show your desktop?

Also, when the monitor is blank, does trying to switch to another virtual terminal work? In many default configurations, Ctrl+Alt+F3 will open a new virtual terminal and Ctrl+Alt+F2 will return to your graphical session.

Thanks!

And sorry for the double email here, but basically what I'm trying to figure out is if it's your computer going to sleep that's causing the problem, or if it's the monitor - so that process is to try to isolate those and see if the monitor powering off on its own is enough to trigger it.

Thanks!

Ok, did all (hopefully :)

First off, ALL tests below work as expected with X11.

Results with Wayland:

Test 1: Wait 1 Minute until monitors sleep:
- Monitors blanked
- Pressed a  key on the keyboard
- KDE came back again
- Switching to a virtual terminal Alt-Ctrl-F3 doesn't show up
- Switching back to Alt-Ctrl-F2 (KDE) shows me only the mouse cursor, no GUI

--rebooting--

Test 2:
Using my shortcut for Suspend (defined in KDE preferences):
- Hardrive is saving, screens are blanking, and CPU is turned off
- Pressed a  key on the keyboard
- Computer starts again (I can hear the fan starting up again)
- Monitors keep sleeping
- No text console shows up with Alt-Ctrl-F3
- No KDE shows up with Alt-Ctrl-F2
- Monitors just sleep

Any more tests? Or logfile entries where I can look into?

Maybe another important fact:

When I was logged in with X11 and wanted to try the tests, I first just logged our from X11 to sddm and wanted to log in with Wayland. After the password it only showed me the mouse cursor then and no KDE or plasma.

I always had to hard-reboot and log in (freshly) with Wayland to get it starting up for my test with Wayland.

Update: With Plasma 6.3.5 it wakes up from suspend! So this bug seems to be fixed somehow.

But a new bug is now detected. The background is glitched with old information from the old session (SDDM was completely normal after resume from suspend). But then back in my Wayland session, I cannot even see my bottom panel. Only new windows are drawn correctly. I attached a screenshot for better understanding.

Created attachment 182478 [details]
Mixed up desktop after resume from suspend in Wayland

(In reply to pietz from comment #9)
> Created attachment 182478 [details]
> Mixed up desktop after resume from suspend in Wayland

I'm sorry that you experienced a new bug after the original one was fixed. We do ask that there be only one issue per report. Please open a new bug report for the screen corruption after resuming. Thanks!

I'll close this one out.

With Plasma 6.3.6 this bug is back again. Suspending works, but no wake up. The computer is resuming (fan is starting up) but no graphics. Also Alt-F3 doesn't turn on the monitor.

(In reply to pietz from comment #11)
> With Plasma 6.3.6 this bug is back again. Suspending works, but no wake up.
> The computer is resuming (fan is starting up) but no graphics. Also Alt-F3
> doesn't turn on the monitor.

When the system is in this state, are you able to get to a TTY with Ctrl+Alt+F3? Do you see a login prompt?
I'm still trying to determine if the monitor is on and receiving a signal. Thanks.

Black screen with mouse cursor
https://bugs.kde.org/show_bug.cgi?id=505201

🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME.

For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging.

Thank you for helping us make KDE software even better for everyone!

(In reply to TraceyC from comment #12)
> When the system is in this state, are you able to get to a TTY with
> Ctrl+Alt+F3? Do you see a login prompt?
> I'm still trying to determine if the monitor is on and receiving a signal.
> Thanks.

We're still waiting on this information. Please don't change this back to REPORTED until you've provided the answer.

Oh ok. Sorry.

This behavior changed over time (and updates from Kubuntu with backports PPA enabled). Graphical resuming never worked. But sometimes in the past I was able to resume the monitors over the TTY console (e.g. Ctrl-Alt-F3 etc.).

But now, using Plasma 6.3.6 and KDE framework 6.14.0 the TTYs don't bring up my screens back again at all. I have to reset my computer with the hardware button. I haven't tried if my machine is reachable over ssh. Should I? Or is the previous information enough for the bug?

Everything just works with X11 as expected. Only Wayland has that issue with not coming back from suspend mode.

I really can help with information, just tell me what you need :)

Thanks!

Thanks for your reply. I'm sorry this is happening again for you.

There might be something in the system logs that helps. Can you try reproducing the bug and then running this command? For the date and time, use the time about a minute before you put the system to sleep.

journalctl --since "2025-07-24 15:10:00"  | grep org_kde_powerdevil

Then paste the output into this report. Thanks!

Created attachment 183510 [details]
journalctl one minute before suspending with grep org_kde_powerdevil

Done :) See my output in the attachment.

Seems like there are some i2c-permissions as far as I can interpret for a fast look... But I have really not detailed knowledge about this layer.

Thanks for the logs, that's useful. That looks like the same errors as in bug 506259, although the symptoms are different.  I'll let the developers take a closer look.

Pasting the logs here to make them searchable, since they're short

Jul 25 18:03:44 korn org_kde_powerdevil[4175]: Starting libddcutil. library built Feb 22 2025 at 15:37:45. stdout_stderr_redirected=true
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: Failed to create wl_display (No such file or directory)
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: Initializing libddcutil.  ddcutil version: 2.2.0-dev, shared library: /usr/lib/x86_64-linux-gnu/libddcutil.so.5.2.0
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: [  4175] Options passed from client:
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: [  4175] Applying combined libddcutil options:
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: [  4175] Device /dev/i2c-4 lacks R/W permissions
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: [  4175] Device /dev/i2c-5 lacks R/W permissions
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: Library initialization complete.
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: [  4175] Watching for display connection changes, resolved watch mode = Watch_Mode_Xevent, poll loop interval = 100 millisec
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: [  4175]                                          extra_stabilization_millisec: 0,  stabilization_poll_millisec: 100
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: [  4175] libddcutil recheck thread (nil) started
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: [  4175] libddcutil watch thread 0x607c45ac6490 started
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: [  4175] Error(s) opening ddc devices
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: Error(s) opening ddc devices
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: Error EACCES(-13): Permission denied opening /dev/i2c-4
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: Error EACCES(-13): Permission denied opening /dev/i2c-5
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: [  4175] Error EACCES(-13): Permission denied opening /dev/i2c-4
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: [  4175] Error EACCES(-13): Permission denied opening /dev/i2c-5
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: org.kde.powerdevil: org.kde.powerdevil.chargethresholdhelper.getthreshold failed "Charge thresholds are not supported by the kernel for this hardware"
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: org.kde.powerdevil: org.kde.powerdevil.backlighthelper.brightness failed
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: [  4210] (dw_recheck_displays_func) Recheck interval: Slept for 200 millisec
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: org.kde.powerdevil: Handle button events action could not check for screen configuration
Jul 25 18:03:45 korn org_kde_powerdevil[4175]: org.kde.powerdevil: org.kde.powerdevil.chargethresholdhelper.getthreshold failed "Charge thresholds are not supported by the kernel for this hardware"

Thanks! :-D