pci_set_power_state -- Set power management state of a device.
(struct pci_dev * dev, int new_state);
PCI device for which PM is set
new power management statement (0 == D0, 3 == D3, etc.)
Set power management state of a device. For transitions from state D3
it isn't as straightforward as one could assume since many devices forget
their configuration space during wakeup. Returns old power state.