Created attachment 192927 [details]
Verbose boot dmesg.
I'm aware that to control backlight you have to use graphics/intel-backlight (is there any chance to see this exposed to sysctl in the future without needing this kludge?) -- and it works if I bind it to some window manager keys.
However, I can not use the brightness keys via window manager nor devd, because they generate no events at all. I have tried loading different acpi_* kernel modules, and none of them work.
This has always been the case, since version 9, and I have not used any earlier version.
Created attachment 192928 [details]
These errors show up at random, are they relevant?
I forgot to add: brightness works up until the kernel is loader. And the brightness set by intel-backlight does not survive suspend restore -- it is reset to the pre-kernel setting.