Rebooted with acpi_backlight=vendor - backlight applet and hotkeys work fine. Attaching more stuff ...
echo 8 > /sys/class/backlight/intel_backlight/brightness does change the backlight brightness, to dark or near-dark.
Rebooted with acpi_backlight= vendor - backlight applet and hotkeys work fine. Attaching more stuff ...
echo 8 > /sys/class/ backlight/ intel_backlight /brightness does change the backlight brightness, to dark or near-dark.