PoFxSetComponentWake function

The PoFxSetComponentWake routine indicates whether the driver arms the specified component to wake whenever the component enters the idle condition.


  POHANDLE Handle,
  ULONG    Component,
  BOOLEAN  WakeHint



A handle that represents the registration of the device with the power management framework (PoFx). The device driver previously received this handle from the PoFxRegisterDevice routine.


The index that identifies the component. This parameter is an index into the Components array in the PO_FX_DEVICE structure that the device driver used to register the device with PoFx. If the Components array contains N elements, component indexes range from 0 to N–1.


Whether the driver arms the component to wake whenever the component enters the idle condition. If TRUE, the driver arms the component to wake. If FALSE, the driver does not arm the component to wake.

Return Value



Before a component enters a low-power Fx state, the driver might arm the component to automatically wake in response to an input signal from an external source (for example, if the user pushes a button). The WakeHint parameter informs PoFx whether the driver arms the component to wake. If a component is armed to wake, PoFx will not switch the component to a low-power Fx state from which the component cannot wake.

When a device is registered with PoFx, the registration information for each component in the device is contained in a separate PO_FX_COMPONENT structure. The DeepestWakeableIdleState member of this structure specifies the deepest Fx state from which the component can wake.

The device driver can call PoFxSetComponentWake each time a change in conditions requires a change in the WakeHint value. After each call, the new WakeHint value remains in effect until the driver calls PoFxSetComponentWake again to update it.

If a component is in the idle condition when PoFxSetComponentWake is called, PoFx might change the component’s Fx state to accommodate the new WakeHint parameter value specified by the caller.


Windows version Available starting with Windows 8.
Target Platform Universal
Header wdm.h
Library Ntoskrnl.lib
DLL Ntoskrnl.exe

See Also