Comment 50 for bug 538256

The problem is actually kernel modesetting (KMS). With KMS, the kernel takes over control of the screen brightness completely, and ACPI no longer gets to control things. The correct thing to do is to some how hook up the ACPI keys (Fn+{up,down}) to the setpci commands. However, it is unclear at what level all this should happen... Can we use/abuse things like upower? Or is the acpid script the cleanest way to proceed?