There's no generic ACPI mechanism for this. Some machines with dual GPUs have ACPI methods for turning the discrete controller on and off, but in general you'd be looking at doing this from the GPU driver. -- Matthew Garrett | mjg59@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html