Bug 503229

SUMMARY
Asus Rog Flow X13 GV301RE laptop
Recently, the display brightness adjustment using the sliders in the interface and the buttons on the keyboard stopped working, but the adjustment animation is present (honestly, the display brightness adjustment worked immediately after installation). The keyboard backlight is adjusted as usual.
I dug around on the Internet and found an option to adjust via the command line with a utility:

root@ROG:/home/mohn# brightnessctl
Device 'amdgpu_bl1' of class 'backlight':
Current brightness: 0 (0%)
Max brightness: 255

Then I dug up how to set the brightness without this utility:
echo 0 > /sys/class/backlight/amdgpu_bl1/brightness
the command above sets the minimum brightness, if you replace 0 with 255, you can set the maximum.
Now the task: how to fix brightness adjustment with sliders in the KDE interface and keyboard buttons?

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Debian 12  6.1.0-33-amd64
KDE Plasma Version: 5.27.5
Wayland and X11

Linux/KDE Plasma: Debian 13 6.12.22-amd64
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.11.0
Qt Version: 6.8.2
Wayland and X11

Linux: Live Fedora KDE 42

gddccontrol is not sopported my display

On Debian 12:
$ sudo journalctl -xe
Subject: Unit succeeded
░░ Defined-By: systemd
░░ Support: https://www.debian.org/support
░░
░░ The unit packagekit.service has successfully entered the 'dead' state.
апр 23 15:26:22 ROG systemd[1]: packagekit.service: Consumed 4.806s CPU time.
░░ Subject: Потребленные юнитом ресурсы
░░ Defined-By: systemd
░░ Support: https://www.debian.org/support
░░
░░ Юнит packagekit.service завершен. Приводится статистика по потребленным им ресурсам.
апр 23 15:27:13 ROG plasmashell[3068]: [3117:3122:0423/152713.933606:ERROR:ssl_client_socket_impl.cc(1097)] handshake failed; returned -1, SSL error code 1, net_error -101
апр 23 15:27:38 ROG sudo[7443]: pam_unix(sudo:session): session closed for user root
апр 23 15:27:42 ROG kernel: asus 0003:0B05:19B6.0004: Unmapped Asus vendor usagepage code 0xec
апр 23 15:27:42 ROG dbus-daemon[862]: [system] Activating service name='org.kde.powerdevil.backlighthelper' requested by ':1.97' (uid=1000 pid=1752 comm="/usr/lib/x86_64-linux-gnu/libexec>
апр 23 15:27:42 ROG dbus-daemon[862]: [system] Successfully activated service 'org.kde.powerdevil.backlighthelper'
апр 23 15:27:44 ROG kernel: asus 0003:0B05:19B6.0004: Unmapped Asus vendor usagepage code 0xec
апр 23 15:27:44 ROG kernel: asus 0003:0B05:19B6.0004: Unmapped Asus vendor usagepage code 0xec
апр 23 15:27:47 ROG kernel: asus 0003:0B05:19B6.0004: Unmapped Asus vendor usagepage code 0xec
апр 23 15:27:48 ROG kernel: asus 0003:0B05:19B6.0004: Unmapped Asus vendor usagepage code 0xec
апр 23 15:27:50 ROG kernel: asus 0003:0B05:19B6.0004: Unmapped Asus vendor usagepage code 0xec
апр 23 15:27:50 ROG kernel: asus 0003:0B05:19B6.0004: Unmapped Asus vendor usagepage code 0xec
апр 23 15:27:54 ROG kernel: asus 0003:0B05:19B6.0004: Unmapped Asus vendor usagepage code 0xec
апр 23 15:27:54 ROG sudo[8125]:     root : TTY=pts/3 ; PWD=/home/mohn ; USER=root ; COMMAND=/usr/bin/journalctl -xe
апр 23 15:27:54 ROG sudo[8125]: pam_unix(sudo:session): session opened for user root(uid=0) by (uid=0)