you can try extracting your dsdt with maciasl app and applying this simple PNLF patch
# Brightness control fix
into device label PNLF remove_entry;
into scope label \_SB insert
begin
Device (PNLF)\n
{\n
Name (_HID, EisaId ("APP0002"))\n
Name (_CID, "backlight")\n
Name (_UID, 10)\n
Name (_STA, 0x0B)\n
}\n
end;