> it can be a problem when it increases latency or wastes CPU cycles I think it wastes power. On a setup with interrupts, you could clock gate the host contro

> it can be a problem when it increases latency or wastes CPU cycles I think it wastes power. On a setup with interrupts, you could clock gate the host controller and if the device needs to say something it can raise the interrupt line and wake up the host. I don't think there's a way to clock gate a USB1 controller and then do e.g. wake on LAN.