Adaptive peripheral component interconnect express link substate initiation for optimal performance and power savings

Abstract

Systems, methods, and apparatus for adaptively modifying latency times governing entry of a PCIe interface into low power states are described. A method performed by a controller of a PCIe interface includes determining that a burst of data is being transmitted on a PCIe link, configuring a timer to signal when an entry latency period has elapsed after determining that a PCIe link has entered an idle state, causing one or more circuits of the PCIe interface to enter a low-power state when the timer signals that the entry latency period has elapsed before the PCIe link becomes active, and increasing the entry latency period when a number of entries of the PCIe interface to the low-power state that occurs during transmission of the burst of data exceeds a threshold maximum number.