EvtDeviceQueryRemove function

[Applies to KMDF and UMDF]

A driver's EvtDeviceQueryRemove event callback function determines whether a specified device can be stopped and removed.

Syntax

C++


EVT_WDF_DEVICE_QUERY_REMOVE EvtDeviceQueryRemove;

NTSTATUS EvtDeviceQueryRemove(
  _In_  WDFDEVICE Device
)
{ ... }

Parameters

Device [in]: A handle to a framework device object.

Return value

If the driver determines that the device can be stopped and removed, the EvtDeviceQueryRemove callback function must return STATUS_SUCCESS or another status value for which NT_SUCCESS(status) equals TRUE. Otherwise it must return a status value for which NT_SUCCESS(status) equals FALSE. Do not return STATUS_NOT_SUPPORTED.

Remarks

To register an EvtDeviceQueryRemove callback function, a driver must call WdfDeviceInitSetPnpPowerEventCallbacks.

If the device and driver support idle power-down, the device might not be in its working state when the framework calls the driver's EvtDeviceQueryRemove callback function. The callback function can call WdfDeviceStopIdle to force the device into its working (D0) state, and then the callback function can call WdfDeviceResumeIdle before it returns.

For more information about the EvtDeviceQueryRemove callback function, see Handling Requests to Stop a Device.

The framework does not synchronize the EvtDeviceQueryRemove callback function with other PnP and power management callback functions. For information about how the framework synchronizes the execution of a driver's event callback functions, see Using Automatic Synchronization.

Examples

To define an EvtDeviceQueryRemove callback function, you must first provide a function declaration that identifies the type of callback function you’re defining. Windows provides a set of callback function types for drivers. Declaring a function using the callback function types helps Code Analysis for Drivers, Static Driver Verifier (SDV), and other verification tools find errors, and it’s a requirement for writing drivers for the Windows operating system.

For example, to define an EvtDeviceQueryRemove callback function that is named MyDeviceQueryRemove, use the EVT_WDF_DEVICE_QUERY_REMOVE type as shown in this code example:


EVT_WDF_DEVICE_QUERY_REMOVE  MyDeviceQueryRemove;

Then, implement your callback function as follows:


_Use_decl_annotations_
NTSTATUS
 MyDeviceQueryRemove (
    WDFDEVICE  Device
    )
 {...}

The EVT_WDF_DEVICE_QUERY_REMOVE function type is defined in the Wdfdevice.h header file. To more accurately identify errors when you run the code analysis tools, be sure to add the _Use_decl_annotations_ annotation to your function definition. The _Use_decl_annotations_ annotation ensures that the annotations that are applied to the EVT_WDF_DEVICE_QUERY_REMOVE function type in the header file are used. For more information about the requirements for function declarations, see Declaring Functions by Using Function Role Types for KMDF Drivers. For information about _Use_decl_annotations_, see Annotating Function Behavior.

Requirements

Minimum KMDF version	1.0
Minimum UMDF version	2.0
Header	Wdfdevice.h (include Wdf.h)
IRQL	PASSIVE_LEVEL