Display brightness

Support
1

After fresh installation i can’t adjust brightness slide in user session first boot mode

Its adjustable only on second boot option system maintenance tasks.

2

Its always on max . it should be adjustable

Any fix?

1 Like
3

We had a similar issue in the past.
(xfce4-power-manager xfpm-power-backlight-helper pkexec lxsudo popup - Development - Whonix Forum)

Back then the solution was a sudoers exception. That won’t work nowadays due to user-sysmaint-split.

This will be looked into before Kicksecure 18 (Debian trixie based) release.

4

me had same issuee dn’t no y it set to max ? shuld be set to 75 or 80

5

I tried all fixes from google without any result.

Hopefully the problem will be solved with the Kicksecure 18 , otherwise my Kicksecure remains unusable.

6

Fixed in Kicksecure 18.

7

Very pleased to hear that you’ve resolved the problem

Only Kicksecure 17 are visible on download site

What’s the link for Kicksecure 18 xfce ISO

Appreciate it

8

There will be a new once available.

10

Also possible on 18 xfce or only Lxqt ?

11

Kicksecure 18 + Xfce backlight changing:

Try running:

backlight-tool-dist
12

Fine

On Debian xbacklight doesn’t work until this fix →

If you get the “No outputs have backlight property” error, it is because xrandr/xbacklight does not choose the right directory in /sys/class/backlight. You can specify the directory by setting the Backlight option of the device section in xorg.conf. For instance, if the name of the directory is intel_backlight, the device section can be configured as follows:

/etc/X11/xorg.conf

Section “Device”
Identifier “Card0”
Driver “intel”
Option “Backlight” “intel_backlight”
EndSectio

Will Xbacklight work with Kicksecuere 17 so i can go back to it ?

13

Untested, but if xbacklight works by telling the X server to modify the brightness values itself, and X is running as root, it will likely work.

The core reason things broke in this area in the first place is that modifying files under /sys/class/backlight requires root access. We previously had sudoers config in place that allowed Xfce utilities to modify the backlight files by running sudo without needing a password, but when we introduced user-sysmaint-split that broke. In Kicksecure 18, backlight-tool-dist uses privleap (a simpler, more restrictive privilege escalation framework) to do backlight changes, which is a lot safer than when we were doing it with sudo and still works. That tool isn’t available for Kicksecure 17 though.

Any tool that requires direct root access to modify the backlight brightness will not work on Kicksecure 17. Tools that are able to circumvent this requirement (by, for instance, running a privileged systemd service that listens for backlight change requests from unprivileged processes) will likely work. (This is also why backlight tools work normally in sysmaint mode - the sysmaint account has access to tools like sudo and pkexec, and so backlight adjustment tools that rely on sudo and pkexec are able to function normally there.)

1 Like