Hi everyone, first post here as I am trying to track down some information.
I am using a Dell XPS 15 which has an OLED display. On various distributions since I have owned it (including Manjaro previously) I had to use icc-brightness or similar to get brightness control working.
I did a new Manjaro install recently and when I updated from 5.8 to 5.9 kernel I had brightness working with nothing else required which I was surprised and happy about as the icc method always felt pretty hacky. I assumed that this was now natively supported in the 5.9 kernel as I knew there were a lot of new features in it.
In the last couple of days I tried out OpenSUSE Tumbleweed and discovered that with 5.9 kernel I did not have brightness control. So as you do I went looking and found nothing relating to 5.9 kernel and OLED screens. I then tested my Manjaro install again and indeed on 5.9.11-3 I have brightness but 5.8.12-1 I do not (Unfortunately I didn’t note the full SUSE kernel version).
Checking the arch wiki, it recommends installing linux-oled from AUR in order to get backlight control (wiki archlinux org/index.php/Dell_XPS_15_7590#Backlight).
My question is, can anyone point me in the direction of what is providing the OLED backlight control? Is manjaro auto-detecting my hardware and patching the kernel with the above? I find it unlikely. Or is this a kernel feature?