WdfDeviceGetDevicePowerState function (wdfdevice.h)

[Applies to KMDF only]

The WdfDeviceGetDevicePowerState method returns the current state of the framework's power state machine, for a specified device.

Syntax

WDF_DEVICE_POWER_STATE WdfDeviceGetDevicePowerState(
  [in] WDFDEVICE Device
);

Parameters

[in] Device

A handle to a framework device object.

Return value

WdfDeviceGetDevicePowerState returns a WDF_DEVICE_POWER_STATE-typed enumerator that identifies the current state of the framework's power state machine for the specified device.

A bug check occurs if the driver supplies an invalid object handle.

Remarks

For more information about the framework's state machines, see State Machines in the Framework.

The WdfDeviceGetDevicePowerState method returns a meaningful value only if it is called from within the following callback functions:

• EvtDevicePrepareHardware

• EvtDeviceReleaseHardware

• EvtDeviceD0Entry

• EvtDeviceD0EntryPostInterruptsEnabled

• EvtDeviceD0Exit

• EvtDeviceD0ExitPreInterruptsDisabled

• EvtDeviceSelfManagedIoInit

• EvtDeviceSelfManagedIoSuspend

• EvtDeviceSelfManagedIoRestart

Examples

The following code example obtains the current state of the framework's power state machine for a specified device.

WDF_DEVICE_POWER_STATE state;

state = WdfDeviceGetDevicePowerState(Device);

Requirements

See also

WdfDevStateNormalize

WdfDeviceGetDevicePnpState

WdfDeviceGetDevicePowerPolicyState