_WDF_STATE_NOTIFICATION_TYPE Enumeration

[Applies to KMDF only]

The WDF_STATE_NOTIFICATION_TYPE enumeration identifies the type of Plug and Play, power, or power policy notification that a framework-based driver will receive.

Syntax

typedef enum _WDF_STATE_NOTIFICATION_TYPE {
  StateNotificationInvalid           ,
  StateNotificationEnterState        ,
  StateNotificationPostProcessState  ,
  StateNotificationLeaveState        ,
  StateNotificationAllStates
} WDF_STATE_NOTIFICATION_TYPE;

Constants

StateNotificationInvalid For internal use only.
StateNotificationEnterState The driver is notified immediately before a device's Plug and Play, power, or power policy state machine enters a specified state.
StateNotificationPostProcessState The driver is notified immediately after a device's Plug and Play, power, or power policy state machine enters a specified state.
StateNotificationLeaveState The driver is notified immediately before a device's Plug and Play, power, or power policy state machine leaves a specified state.
StateNotificationAllStates The driver receives enter-state, postprocess-state, and leave-state notifications.

Remarks

When the framework's state machine for a driver's device changes from state a to state b, the framework notifies the driver (if the driver registered an appropriate event callback function), in the following sequence:

  1. Calls state a's leave-state notification callback function.

  2. Calls state b's enter-state notification callback function.

  3. Changes the device's state from a to b.

  4. Calls state b's postprocess-state notification callback function.

To register for notification of a change in state, the driver can call the following methods:

Requirements

   
Minimum KMDF version 1.0
Header wdfdevice.h (include Wdf.h)

See Also

WDF_DEVICE_PNP_NOTIFICATION_DATA

WDF_DEVICE_POWER_NOTIFICATION_DATA

WDF_DEVICE_POWER_POLICY_NOTIFICATION_DATA