want better acpi nexus
The current ACPI nexus driver seems to be quite limited. While working on 6441 I wasn't able to figure out how to get a notification when a new ACPI device is added to the system (such as an extra battery). It seems devices need to be enumerated manually, and then ACPI objects can be initialized for them and have notifications attached to them. Also, for some very odd reason ACPI drivers are pseudo drivers despite controlling hardware.
It would be much better if the ACPI nexus driver would present itself as a self-identifying bus, using some sort of notification from acpica for device add/removal. Drivers for various ACPI devices like batteries, AC adapters, etc. should be simple device drivers that attach several times for each such device.