EvtDeviceSelfManagedIoInit function

[Applies to KMDF and UMDF]

A driver's EvtDeviceSelfManagedIoInit event callback function initializes and starts the device's self-managed I/O operations.

Syntax

C++


EVT_WDF_DEVICE_SELF_MANAGED_IO_INIT EvtDeviceSelfManagedIoInit;

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

Parameters

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

Return value

If the EvtDeviceSelfManagedIoInit callback function encounters no errors, it 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. If NT_SUCCESS(status) equals FALSE, the framework does not start the device.

If NT_SUCCESS(status) equals FALSE, the framework calls the driver's EvtDeviceSelfManagedIoFlush and EvtDeviceSelfManagedIoCleanup callback functions.

For more information about this callback function's return values, see Reporting Device Failures.

Remarks

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

If the driver has registered an EvtDeviceSelfManagedIoInit callback function, the framework calls it once for each device, after the framework has called the driver's EvtDeviceD0Entry callback function for the first time. The framework does not call the EvtDeviceSelfManagedIoInit callback function again for that device, unless the device is removed and reconnected, or the drivers are reloaded.

The EvtDeviceSelfManagedIoInit callback function must initialize and start the self-managed I/O operations that the driver will handle for the device.

For more information about when the framework calls this callback function, see PnP and Power Management Scenarios.

For more information about drivers that provide this callback function, see Using Self-Managed I/O.

Examples

To define an EvtDeviceSelfManagedIoInit 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 EvtDeviceSelfManagedIoInit callback function that is named MyDeviceSelfManagedIoInit, use the EVT_WDF_DEVICE_SELF_MANAGED_IO_INIT type as shown in this code example:


EVT_WDF_DEVICE_SELF_MANAGED_IO_INIT  MyDeviceSelfManagedIoInit;

Then, implement your callback function as follows:


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

The EVT_WDF_DEVICE_SELF_MANAGED_IO_INIT 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_SELF_MANAGED_IO_INIT 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