Increasing System Power Efficiency Through Driver Support for Runtime Idle Detection
One way to improve a computer's power efficiency is to power down devices that aren't currently being used, even though the system may still be active and in its normal operating power state (S0). The practice of powering down an idle device while the system remains running is referred to as "Runtime idle detection" or "S0 idle." A USB function driver supports runtime idle detection by implementing USB selective suspend. This white paper provides advice for driver developers on how to modify their function drivers to support runtime idle detection.