WdfUsbTargetPipeFormatRequestForAbort method

[Applies to KMDF and UMDF]

The WdfUsbTargetPipeFormatRequestForAbort method builds an abort request for a specified USB pipe, but it does not send the request.

Syntax

NTSTATUS WdfUsbTargetPipeFormatRequestForAbort(
  [in]  WDFUSBPIPE Pipe,
  [in]  WDFREQUEST Request
);

Parameters

Pipe [in]

A handle to a framework pipe object that was obtained by calling WdfUsbInterfaceGetConfiguredPipe.

Request [in]

A handle to a framework request object. For more information, see the following Remarks section.

Return value

WdfUsbTargetPipeFormatRequestForAbort returns the I/O target's completion status value if the operation succeeds. Otherwise, this method can return one of the following values:

This method also might return other NTSTATUS values.

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

Remarks

Use WdfUsbTargetPipeFormatRequestForAbort, followed by WdfRequestSend, to send a USB abort request either synchronously or asynchronously. Alternatively, use the WdfUsbTargetPipeAbortSynchronously method to send a request synchronously.

A USB abort request causes the driver's I/O target to cancel all of the I/O requests that have been sent to a pipe. When a driver calls WdfRequestSend, the framework sends a URB_FUNCTION_ABORT_PIPE request to the I/O target. For more information about canceling operations on a USB pipe (also called "aborting a pipe"), see the USB specification.

You can forward an I/O request that your driver received in an I/O queue, or you can create and send a new request.

To forward an I/O request that your driver received in an I/O queue, specify the received request's handle for the WdfUsbTargetPipeFormatRequestForAbort method's Request parameter.

To create a new I/O request, call WdfRequestCreate to preallocate a request object. Supply the request handle for the WdfUsbTargetPipeFormatRequestForAbort method's Request parameter. You can reuse the request object by calling WdfRequestReuse. Your driver's EvtDriverDeviceAdd callback function can preallocate request objects for a device.

After calling WdfUsbTargetPipeFormatRequestForAbort to format an I/O request, the driver must call WdfRequestSend to send the request (either synchronously or asynchronously) to an I/O target.

Multiple calls to WdfUsbTargetPipeFormatRequestForAbort that use the same request do not cause additional resource allocations. Therefore, to reduce the chance that WdfRequestCreate will return STATUS_INSUFFICIENT_RESOURCES, your driver's EvtDriverDeviceAdd callback function can call WdfRequestCreate to preallocate one or more request objects for a device. The driver can subsequently reuse (call WdfRequestReuse), reformat (call WdfUsbTargetPipeFormatRequestForAbort), and resend (call WdfRequestSend) each request object without risking a STATUS_INSUFFICIENT_RESOURCES return value from a later call to WdfRequestCreate. All subsequent calls to WdfUsbTargetPipeFormatRequestForAbort for the reused request object will return STATUS_SUCCESS, if parameter values do not change. (If the driver does not call the same request-formatting method each time, additional resources might be allocated.)

For information about obtaining status information after an I/O request completes, see Obtaining Completion Information.

For more information about the WdfUsbTargetPipeFormatRequestForAbort method and USB I/O targets, see USB I/O Targets.

Examples

The following code example formats an abort request for a USB pipe, registers a CompletionRoutine callback function, and sends the request.

status = WdfUsbTargetPipeFormatRequestForAbort(
                                               pipe,
                                               Request
                                               );
if (!NT_SUCCESS(status)) {
    goto Exit;
}

WdfRequestSetCompletionRoutine(
                               Request,
                               AbortCompletionRoutine,
                               pipe
                               );

if (WdfRequestSend(
                   Request,
                   WdfUsbTargetPipeGetIoTarget(pipe),
                   WDF_NO_SEND_OPTIONS
                   ) == FALSE) {
    status = WdfRequestGetStatus(Request);
    goto Exit;
}
Exit:
if (!NT_SUCCESS(status)) {
    WdfRequestCompleteWithInformation(
                                      Request,
                                      status,
                                      0
                                      );
}
return;

Requirements

See also

WdfUsbInterfaceGetConfiguredPipe

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