Although I don't ever touch the input subsystem, I figured I'd toss in my opinion. HAL and evdev may not be required, but in the future we really don't want policy and per-device drivers where we don't need them. HAL lets us make a lot of device configuration simpler when paired with evdev, and also lets us have one central place for storing policies. You can disable HAL, but we're moving in that direction regardless. ~ C.