Copyright c Rafael J. This document only covers the aspects of power management specific to PCI devices. In general, power management is a feature allowing one to save energy by putting devices into states in which they draw less power low-power states at the price of reduced functionality or performance. Usually, a device is put into a low-power state when it is underutilized or completely inactive.
[PATCH 2/3] PCI / PM: Make PCIe PME interrupts wake up from "freeze" sleep state
PCI / ACPI PM: Platform support for PCI PME wake-up [taru.info]
When your computer first boots, PCIe is what determines the devices that are attached or plugged in to the motherboard. It identifies the links between each device, creating a traffic map and negotiates the width of each link. This identification of devices and connections uses the same protocol as PCI, so no changes were required when changing from PCI to PCIe in either software or operating systems. A PCIe connection consists of one or more up to sixteen, at the moment data-transmission lanes, connected serially. Each lane consists of two pairs of wires, one for transmitting and one for receiving. There are 1, 4, 8 or 16 lanes in a single PCIe slot — denoted as x1, x4, x8, or x
PCIe Lanes explained
They will wake up from sleep S3 OK. When the computers are shut down, there is no power going to the network interface, that is, there is no link light on the network jack. So, of course, the network interface never sees the WOL magic packet. The computer systems are from Lenovo and are a couple different models although they both are using the same chipset on the motherboards and same network interface , one a ThinkCenter M series desktop SFF system and another one a ThinkStation P series engineering workstation. They are using an on-board Intel ILM network interface.
Comment 4 rezwanul kabir UTC. Comment 5 Rafael J. Wysocki UTC.