Plasma power management woes and solutions

Updated: December 27, 2024

Until recently, my Slimbook Executive laptop has worked beautifully. For a year, it had a spotless record, it worked elegantly, without any major issues or errors. Then, in a span of just one month, so many things went badly, a result of poorly tested and integrated firmware and system updates that turned my sweet machine into a nerdy sandbox. In fact, I don't care why or how, the end result was: keyboard issues, mouse issues, network management issues, power management issues.

My tribulations are outlined in three progressive worse long-term reports on my usage of this machine, from the mildly skeptical fifth to angry sixth to fully disenchanted and bitter seventh article on this topic. Sure, a fresh wave of updates did resolve most of the problems, but not all. Power management remains iffy. However, I think I'm starting to see a pattern, and there may be some workarounds. If you're a Kubuntu 22.04 user, and your Plasma box is experiencing some weird power management problems, I might be able to help.

Problem manifestation

The following issues have affected my system since:

A kernel update has resolved some of the above, but there's a brand new manifestation:

Workarounds

It took me a couple of weeks to discern all these patterns above. I also tried all sorts of little tricks that might help, and eventually they do. Now please note, prior to the kernel update outlined in the seventh article, which in my case corresponds to the following kernel version: 6.8.0-47-generic, NO workaround did anything. Since, the workarounds are (mostly) effective. Let's outline them.

All right, so what do we have here?

I noticed that changing some of the default settings will help "reset" the power management module. Specifically, for each of the profiles (tabs labeled On AC Power, On Battery, and On Low Batter), change the Dim screen timeout from the default values. Then, untick the Screen Energy Saving checkbox, apply the changes.

Power settings

Restart the power service (on the command line):

systemctl restart --user plasma-powerdevil.service

Go back to Settings, and check the Screen Energy Savings box, apply.

Next, open Settings > Workspace > Startup and Shutdown > Background Services. Here, uncheck KScreen 2, and stop it (the button on the right shows Running, click for it to say Stopped). However, this is not enough, as you will also need to kill a running process.

KScreen service

On the command line, locate and kill:

/usr/lib/x86_64-linux-gnu/libexec/kf5/kscreen_backend_launcher

By the way, the problem is already referenced in this KDE bug report, but hey. And then, just to be on the safe side, restart the power service once more, as I've outlined earlier. This should give you mostly "normal" power management, with all of the profiles doing what they should: screen dimming, blanking and switch off after specified time intervals, and correctly suspend & resume behavior. Works 98% of the time.

The real solution? Removing the actual bugs that cause the problem, but I can't do that - KDE developers can, and I hope they will introduce the necessary changes. The worst kind of bugs are those where the platform you're running is oldish (but still supported), but then you're urged to "upgrade" to a newer version, because maintaining old code is boring and tedious. Happens all too often in the Linux world, and I hope this won't be the case here.

Conclusion

I cannot express how much this string of problems, culminating in the power management issues, has harmed my good feeling about the laptop, about the operating system, about the general prospect of Linux being a viable option for home use. I am fully aware that bugs can happen, but I am also fully aware of the lack of rigor, testing and formal procedures in the software development space, Linux included. I refuse to accept the modern methodologies as the correct way of doing things. I'd rather see things slow down 10x and be tested 10x more, than have to handle random nonsense like the above.

Well, I cannot solve all of the world problems, but I have a laptop I need to use, and use it properly. The workarounds I outlined above helped me quite some. Ideally, they won't be necessary at all, and they will be fixed in the next round of updates. I also cannot promise you will have the same "luck" I have. But since I'm a dreamer and an eternal optimist, please try the tips and tricks I outlined in this tutorial. Namely, fiddle with the timeouts, disable/enable screen switch off, disable KScreen 2, and restart the power service. You might regain your full, peaceful productivity, as it should be. You might. Take care, fellow Don Quixotians.

Cheers.