Buggy brightness adjustment

English Hardware
1

I’m on a fresh install of Tumbleweed (20220616) and for some reason when I try to adjust brightness using the physical brightness keys, it doesn’t work right.

What I mean is: from 0% to 25% brightness everything is fine, the brightness increases by 5% as expected when pressing the “brightness up” key. But from 25%-45% the brightness does not increase at all and when I increase to 50%, brightness drops back down to 5% brightness (although “50%” is displayed on screen) and pressing the “brightness up” key once more takes me back to 0% and the cycle repeats from there.

Sorry if that’s confusing but it’s the best way I can describe it. I’m using an HP laptop 15-bs234wm with Intel UHD 605 graphics. Driver issue? Any help would be greatly appreciated as I’m kind of ignorant on such things.

2

Hi and welcome to the Forum :slight_smile:
Can you check the journalctl output for backlight, on my HP laptops with AMD graphics I have to disable and mask the systemd backlight as it interferes with the gpu brightness control, maybe something similar.


journalctl -b | grep backlight
3

Thank you for the warm welcome and the reply! Here is the output of said command:

Jun 17 18:53:56 localhost systemd[1]: Created slice Slice /system/systemd-**backlight**.
Jun 17 18:53:56 localhost systemd[1]: Starting Load/Save Screen Backlight Brightness of **backlight**:intel_**backli**
ght...
Jun 17 18:53:56 localhost systemd[1]: Finished Load/Save Screen Backlight Brightness of **backlight**:intel_**backli**
ght.
Jun 17 18:54:07 Laptop.home dbus-daemon[639]: [system] Activating service name='org.kde.powerdevil.**backlight**he
lper' requested by ':1.31' (uid=1000 pid=1886 comm="/usr/libexec/org_kde_powerdevil") (using servicehelper)
Jun 17 18:54:07 Laptop.home dbus-daemon[639]: [system] Successfully activated service 'org.kde.powerdevil.**back**
lighthelper'
Jun 17 18:56:27 Laptop.home dbus-daemon[639]: [system] Activating service name='org.kde.powerdevil.**backlight**he
lper' requested by ':1.31' (uid=1000 pid=1886 comm="/usr/libexec/org_kde_powerdevil") (using servicehelper)
Jun 17 18:56:27 Laptop.home dbus-daemon[639]: [system] Successfully activated service 'org.kde.powerdevil.**back**
lighthelper'
Jun 17 18:56:44 Laptop.home dbus-daemon[639]: [system] Activating service name='org.kde.powerdevil.**backlight**he
lper' requested by ':1.31' (uid=1000 pid=1886 comm="/usr/libexec/org_kde_powerdevil") (using servicehelper)
Jun 17 18:56:44 Laptop.home dbus-daemon[639]: [system] Successfully activated service 'org.kde.powerdevil.**back**
lighthelper'
Jun 17 19:15:23 Laptop.home dbus-daemon[639]: [system] Activating service name='org.kde.powerdevil.**backlight**he
lper' requested by ':1.31' (uid=1000 pid=1886 comm="/usr/libexec/org_kde_powerdevil") (using servicehelper)
Jun 17 19:15:23 Laptop.home dbus-daemon[639]: [system] Successfully activated service 'org.kde.powerdevil.**back**
lighthelper'
Jun 17 19:18:29 Laptop.home dbus-daemon[639]: [system] Activating service name='org.kde.powerdevil.**backlight**he
lper' requested by ':1.31' (uid=1000 pid=1886 comm="/usr/libexec/org_kde_powerdevil") (using servicehelper)
Jun 17 19:18:29 Laptop.home dbus-daemon[639]: [system] Successfully activated service 'org.kde.powerdevil.**back**
lighthelper'
Jun 17 19:20:34 Laptop.home dbus-daemon[639]: [system] Activating service name='org.kde.powerdevil.**backlight**he
lper' requested by ':1.31' (uid=1000 pid=1886 comm="/usr/libexec/org_kde_powerdevil") (using servicehelper)
Jun 17 19:20:34 Laptop.home dbus-daemon[639]: [system] Successfully activated service 'org.kde.powerdevil.**back**
lighthelper'
Jun 17 19:21:00 Laptop.home dbus-daemon[639]: [system] Activating service name='org.kde.powerdevil.**backlight**he
lper' requested by ':1.31' (uid=1000 pid=1886 comm="/usr/libexec/org_kde_powerdevil") (using servicehelper)
Jun 17 19:21:00 Laptop.home dbus-daemon[639]: [system] Successfully activated service 'org.kde.powerdevil.**back**
lighthelper'
4

Hi
So it maybe the systemd-backlight:intel_backlight interfering with org.kde.powerdevil.backlighthelper or vice versa.

You could try disabling the systemd service and see what happens…


systemctl stop systemd-backlight@backlight:intel_backlight.service
systemctl disable systemd-backlight@backlight:intel_backlight.service
systemctl mask systemd-backlight@backlight:intel_backlight.service

Reboot and see what happens, to restore run the following and reboot;


systemctl unmask systemd-backlight@backlight:intel_backlight.service
systemctl enable systemd-backlight@backlight:intel_backlight.service

Maybe a Plasma user can offer more suggestions (I’m a GNOME user), oh also are your run Wayland or X11?


echo $XDG_SESSION_TYPE
5

Thank you for the reply! It’s greatly appreciated. I stopped, disabled and masked that service and rebooted (used systemctl for all commands, systemd command wasn’t found). Issue still persisted. Restored the service and was met with this:

zac@Laptop:~> systemctl unmask systemd-backlight@backlight:intel_backlight.service
Removed /etc/systemd/system/systemd-backlight@backlight:intel_backlight.service.
zac@Laptop:~> systemctl enable systemd-backlight@backlight:intel_backlight.service
The unit files have no installation config (WantedBy=, RequiredBy=, Also=,
Alias= settings in the [Install] section, and DefaultInstance= for template
units). This means they are not meant to be enabled using systemctl.
  
Possible reasons for having this kind of units are:
• A unit may be statically enabled by being symlinked from another unit's
  .wants/ or .requires/ directory.
• A unit's purpose may be to act as a helper for some other unit which has
  a requirement dependency on it.
• A unit may be started when needed via activation (socket, path, timer,
  D-Bus, udev, scripted systemctl call, ...).
• In case of template units, the unit is meant to be enabled with some
  instance name specified.

Not sure what this means but could be of some help.
EDIT: Output literally says what it means lol. Sorry, like I said… I’m kind of ignorant.

6

Hi
Did you reboot to see if the service came back systemctl status [email]systemd-backlight@backlight:intel_backlight.servic[/email]e

7

Yes, rebooted and it appears to be back.

Jun 17 21:37:20 localhost systemd[1]: Created slice Slice /system/systemd-**backlight**.
Jun 17 21:37:20 localhost systemd[1]: Starting Load/Save Screen Backlight Brightness of **backlight**:intel_**backli**
ght...
Jun 17 21:37:20 localhost systemd[1]: Finished Load/Save Screen Backlight Brightness of **backlight**:intel_**backli**
ght.
Jun 17 21:37:33 Laptop.home dbus-daemon[647]: [system] Activating service name='org.kde.powerdevil.**backlight**he
lper' requested by ':1.32' (uid=1000 pid=1887 comm="/usr/libexec/org_kde_powerdevil") (using servicehelper)
Jun 17 21:37:33 Laptop.home dbus-daemon[647]: [system] Successfully activated service 'org.kde.powerdevil.**back**
lighthelper'

Forgot to mention, I’m using X11. Should I try to disable and mask .org.kde.powerdevil.backlighthelper?

8

Hi
That (AFAIK) is a desktop feature, so perhaps somewhere in the settings you can change this, you might need to wait for another Plasma user to comment :wink:

9

Okay I’ll hold off on doing anything else until tomorrow. Appreciate all your help and patience!

10

Hi
Sounds like this one…

https://bugs.kde.org/show_bug.cgi?id=399646

and this;

11

Well an update (20220618) fixed the issue. An updated version to powerdevil was present so I’m assuming that’s what fixed it. Thank you again for your help!

12

Thanks for this suggestion @malcomlewis.
Had a similar issue on installing openSUSE Tumbleweed and Leap 15.4.
Followed the instruction - the suggested 3 steps.
Now my display is working fine. HP 15.6" Laptop / AMD / Radeon 5.