I have a 2011 iMac that I can’t get the screen brightness to adjust – no matter what boot parameters that I pass – using either the keyboard or the slider in the menu bar. I can get it to work with:
sudo -i echo [*number 1-255*] > /sys/class/backlight/radeon_bl0/brightness
I have tried the following additions to my boot stanza:
video.use_native_backlight=1 video.use_native_backlight=0 acpi_backlight=video acpi_backlight=vendor acpi_backlight=native acpi_backlight=off
This computer has mutiple partitions with several linux distros (Ubuntu, Fedora, etc.). The following addition to the boot stanza works on those:
I should mention that I use rEFInd as my bootloader. Also, I have updated after each change to the boot stanza using mkinicpio, though I’m not sure if that would actually do anything in the context of boot stanzas.
This makes me think it is a kernel or hook issue in Antergos. But no idea what to change.