apple-gmux-dkms monitor brightness control does not work

[Captain Morgan]

Environment: Ubuntu 22.10, Apple MacPro 2013 Trashcan, Radeon Driver, Display Output Name, WAYLAND0, /sys/class/backlight/gmux_backlight.

Issue: GNOME backlight slider does not adjust external Apple Thunderbolt monitor brightness (WAYLAND0). DDCUI thunderbolt display control /dev/i2c-10, APP, thunderbolt, 37415, adjusts brightness in feature code name x10 (0x02) where brightness is based on ambient light sensor set at 63039, and max brightness is 65535 and can be adjusted to 0.

https://wiki.ubuntu.com/Kernel/AppleGmuxBacklight repository cannot be installed, or does not exist to install and test kernel patch

"Use the following commands to subscribe to the PPA and install the driver.

    sudo add-apt-repository ppa:sforshee/apple-bl-gmux
    sudo apt-get update
    sudo apt-get install apple-gmux-dkms

NOTE: If you previously installed apple-bl-gmux-dkms from this PPA, you be prompted to remove this package when installing apple-gmux-dkms. Please answer yes when prompted, and then reload the apple_bl module by running sudo modprobe -r apple_bl; sudo modprobe apple_bl.

Then to start using the driver you can either reboot, or else use the following commands to reload the driver.

    sudo modprobe -r apple_gmux
    sudo modprobe apple_gmux"

What should it do:
Suppot the backlight GMUX brightness control for external monitor on apple hardware with Radeon graphics using GMUX.

All other methods of enabling brightness control have failed.

[Captain Morgan (captainkhan)]

DDCUI Screenshot:

[Paul White (paulw2u)]

Thank you for reporting this bug to Ubuntu. We are sorry that we do not always have the capacity to review all reported bugs in a timely manner.

Ubuntu 22.10 (kinetic) reached end-of-life on July 20, 2023.

The packages that you refer to are not included in the Ubuntu repositories so they cannot be supported by the Ubuntu project here on Launchpad, for bug reporting at least.

https://launchpad.net/~sforshee/+archive/ubuntu/apple-bl-gmux shows that the packages were only ever prepared for the 'oneiric' and 'precise' releases, the latter release being unsupported since 2017.

https://wiki.ubuntu.com/Kernel/AppleGmuxBacklight was last updated over eleven years ago so like many Wiki pages is now very outdated.

With no activity on this bug report for over a year now I'm closing this as 'Invalid'.