Fedora 35 KDE power settings

Dear Fedora community,

this is my first post in this forum. I apologize for any (surely not intentional!) mistake I will be making in posting this. I would like to ask your help for two issues (but maybe they are related and it is really only one issue) that I am having with Fedora 35 KDE and power management. I have already tried to google this and to search for similar problem in this forum, but without success. I hope I did not miss anything!

First of all, some information about my system (I did a fresh install of Fedora 35 something like a week ago, dual boot with Windows 11):


This is a ThinkPad T14s, first generation.

I did not manually install anything related to kernel and power management: just normal programs I use, like Latex, Spotify, etc… Please note, however, that I have upgraded to version 5.17 of the kernel. (I mention it because I have found here ThinkPad ACPI Driver Picking Up New Features With Linux 5.17 - Phoronix
that this version of the kernel has some changes regarding battery management on thinkpads).

In particular, I never installed tlp. The default power profile daemon seems to be running fine:
Embedded item 2

I have not touched any BIOS options, expect for Secure Boot (disabled) and the Standby option, which I set to “Linux” (it was “Windows”).

Now let me describe my problems (both of them where there before the upgrade to 5.17 and still persist now).

First one. I open KDE system settings. I click power management. I click activity power settings. I click either one of the two other sections (so either energy saving or advanced power settings). The following message appears:
embedded item 3
This is perfectly reproducible (in the sense that it happens to me every time that I follow these steps). Please note that I have exactly written all of my actions, so the message appears even though I have not changed anything.

Second problem. I want to change my battery charging limit (say, to 80%). I do it in this section:
embedded item 4
Then I click apply. No errors. I click somewhere else (anywhere, let us say on “energy saving” for the sake of concreteness). When I return to the section “advanced power settings” the limit is back to 100%.

One last piece of information. I believe that with my configuration I should see the options perfomance, balance, battery saving in the panel widget, like here

However they are not there. This is what I have:
embedded item 5
Now I might be wrong, but I think I had those options before upgrading to 5.17.

I would be happy for any kind of help you can give. By the way, I am really having a good time on my Fedora 35 KDE. This is almost the only problem I had so far.
Again if I have broke any of the good practices that should be observed while posting in this forum do not hesitate to let me know. I would also be happy to give you any other info you may need on my setup.

Thank you in advance,

Damiano

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I am adding the other screenshots here, as I got a message saying that as a new user I can only have at most one embedded item per post.

Embedded item 2:

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Embedded item 3:

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Embedded item 4

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Embedded item 5

I am sorry if this was not the best way to provide you with all of the screenshots. Please let me know if I should have done something different.

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My question does not seem to get much attention. I really hope I have posted it without breaking any rules. Maybe this is simply not the right place. Does anyone know where I could discuss my problem? E.g. do you think that this is related more to KDE than Fedora and that I should be asking to KDE folks?

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It’s only been a day, I’d request you to be patient :slight_smile:

It certainly is the right place—but this isn’t a support forum in the sense that there aren’t people here who are paid to answer questions. Folks will comment if they feel they can help in any way. So it depends on the question, and whether folks here think they have the necessary knowledge to help.

You can of course try the KDE forums too—there will certainly be more people there with KDE knowledge.

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Thank you for your kind reply!
I am in no particular hurry, so no problem waiting on my part! I was simply worried I had asked in the wrong way. I apologise if I gave the impression of ‘demanding’ an answer.
Now I have also posted in KDE Reddit.
We will see :slight_smile:

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I have updates.

First of all, I rebooted and chose the 4.16 version of the kernel form the Grub menu. All of the above problems persist, but now I get the correct “Battery and Brightness” card from the system tray (note the added power profile section with power save, blaanced, performance):

Moreover, I found another Phoronix article that I link here. Maybe it is relevant.

Yet another article that could be useful is linked right at the beginning of the one that I have linked above. I report it here:

Unfortunately I do not really feel that I understand them well enough to know what to do about them, so I am just listing them here.

Moreover, following the advice of a kind reddit user, I ran the two following commands. I am posting here the outputs I got with kernel 4.17, but the outputs of kernel 4.16 seemed pretty equal to me (of course if you want a look at them I can post them too).
Here is the first one:

 [damiano@fedora ~]$ sudo ls -la /sys/class/power_supply/
Place your finger on the fingerprint reader
total 0
drwxr-xr-x.  2 root root 0 Apr 29  2022 .
drwxr-xr-x. 78 root root 0 Apr 29  2022 ..
lrwxrwxrwx.  1 root root 0 Apr 29  2022 AC -> ../../devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:35/PNP0C09:00/ACPI0003:00/power_supply/AC
lrwxrwxrwx.  1 root root 0 Apr 29  2022 BAT0 -> ../../devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:35/PNP0C09:00/PNP0C0A:00/power_supply/BAT0

And here is the second one:

 [damiano@fedora ~]$ sudo ls -la /sys/class/power_supply/BAT*/*
-rw-r--r--. 1 root root 4096 Apr 29 15:33 /sys/class/power_supply/BAT0/alarm
-r--r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/capacity
-r--r--r--. 1 root root 4096 Apr 29 15:33 /sys/class/power_supply/BAT0/capacity_level
-rw-r--r--. 1 root root 4096 Apr 29 15:33 /sys/class/power_supply/BAT0/charge_behaviour
-rw-r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/charge_control_end_threshold
-rw-r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/charge_control_start_threshold
-rw-r--r--. 1 root root 4096 Apr 29 15:33 /sys/class/power_supply/BAT0/charge_start_threshold
-rw-r--r--. 1 root root 4096 Apr 29 15:33 /sys/class/power_supply/BAT0/charge_stop_threshold
-r--r--r--. 1 root root 4096 Apr 29 15:33 /sys/class/power_supply/BAT0/cycle_count
lrwxrwxrwx. 1 root root    0 Apr 29 15:33 /sys/class/power_supply/BAT0/device -> ../../../PNP0C0A:00
-r--r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/energy_full
-r--r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/energy_full_design
-r--r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/energy_now
-r--r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/manufacturer
-r--r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/model_name
-r--r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/power_now
-r--r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/present
-r--r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/serial_number
-r--r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/status
lrwxrwxrwx. 1 root root    0 Apr 29  2022 /sys/class/power_supply/BAT0/subsystem -> ../../../../../../../../../class/power_supply
-r--r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/technology
-r--r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/type
-rw-r--r--. 1 root root 4096 Apr 29  2022 /sys/class/power_supply/BAT0/uevent
-r--r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/voltage_min_design
-r--r--r--. 1 root root 4096 Apr 29 15:32 /sys/class/power_supply/BAT0/voltage_now

/sys/class/power_supply/BAT0/hwmon2:
total 0
drwxr-xr-x. 3 root root    0 Apr 29  2022 .
drwxr-xr-x. 4 root root    0 Apr 29  2022 ..
lrwxrwxrwx. 1 root root    0 Apr 29 15:33 device -> ../../BAT0
-r--r--r--. 1 root root 4096 Apr 29 15:33 in0_input
-r--r--r--. 1 root root 4096 Apr 29 15:33 name
drwxr-xr-x. 2 root root    0 Apr 29 15:33 power
lrwxrwxrwx. 1 root root    0 Apr 29  2022 subsystem -> ../../../../../../../../../../class/hwmon
-rw-r--r--. 1 root root 4096 Apr 29  2022 uevent

/sys/class/power_supply/BAT0/power:
total 0
drwxr-xr-x. 2 root root    0 Apr 29 15:33 .
drwxr-xr-x. 4 root root    0 Apr 29  2022 ..
-rw-r--r--. 1 root root 4096 Apr 29 15:33 autosuspend_delay_ms
-rw-r--r--. 1 root root 4096 Apr 29 15:33 control
-r--r--r--. 1 root root 4096 Apr 29 15:33 runtime_active_time
-r--r--r--. 1 root root 4096 Apr 29 15:33 runtime_status
-r--r--r--. 1 root root 4096 Apr 29 15:33 runtime_suspended_time

I had problem posting this outputs on reddit: in the “code block” it would past everything on the same line…

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UPDATE.

I had a brief exchange of messages on reddit here (I mentioned it before, but I did not provide the link).

At the end, he suggested me to try to manually edit the files

     /sys/class/power_supply/BAT0/charge_stop_threshold

     /sys/class/power_supply/BAT0/charge_control_end_threshold

It did not work, in the sense that I got an error trying to modify those files (even with sudo).

Since then I have updated to Fedora 36 and to Kde 5.24.5. Here the info on my system now:

Now the battery charging limit works!


(Admittedly, the screenshot above does not mean much, because I was able to change the numbers even before, the problem was that they would not be “saved”. What I mean is that now, even if I close System Settings, the values remain as in the screenshot and, of course, the battery stops charging when reaching the threshold.

For the record, I post the output of the last commands that I was suggested by the aforementioned kind reddit user:

[damiano@fedora ~]$ cat /sys/class/power_supply/BAT0/charge_stop_threshold
80
[damiano@fedora ~]$ cat /sys/class/power_supply/BAT0/charge_control_end_threshold
80

so changing the value in Kde System Settings changes the value in both of this files.

The other problems I reported in this thread, i.e. unnecessary notification of changes in the power settings and battery panel applet not showing the different battery modes anymore are still there. However I do not care much about them and at this point I am confident that they will also be fixed soon.