Comment # 24 on bug 956403 from Takashi Iwai

(In reply to Silviu Marin-Caea from comment #20)
> This laptop also has three more buttons for audio mute and volume up, down.
> I don't know if hp_wmi is supposed to handle those too, but I confirm they
> work properly without it.

The other buttons are controlled differently.  The audio buttons are handled
directly by ACPI and sound driver.  The others like the power button are also
handled by ACPI.  Only the WiFi/BT key, the dock station port state and the
ambient light sensor are handled by hp-wmi, AFAIK.