WdfUsbTargetPipeResetSynchronously function

Description

[Applies to KMDF and UMDF]

The WdfUsbTargetPipeResetSynchronously method builds a reset request and sends it synchronously to a specified USB pipe.

Parameters

Pipe [in]

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

Request [in, optional]

A handle to a framework request object. This parameter is optional and can be NULL. For more information, see the following Remarks section.

RequestOptions [in, optional]

A pointer to a caller-allocated WDF_REQUEST_SEND_OPTIONS structure that specifies options for the request. This pointer is optional and can be NULL. For more information, see the following Remarks section.

Return value

WdfUsbTargetPipeResetSynchronously returns the USB 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 the WdfUsbTargetPipeResetSynchronously method to send a USB reset request synchronously. To send such requests asynchronously use WdfUsbTargetPipeFormatRequestForReset, followed by WdfRequestSend.

Before the framework resets the I/O target's USB pipe, it cancels all I/O requests that remain in the I/O target's queue. The driver must not send additional I/O requests to the I/O target until WdfUsbTargetPipeResetSynchronously returns.

The driver must call WdfIoTargetStop before it calls WdfUsbTargetPipeResetSynchronously. After WdfUsbTargetPipeResetSynchronously returns, the driver can call WdfIoTargetStart.

When a driver calls WdfUsbTargetPipeResetSynchronously, the framework sends a URB_FUNCTION_RESET_PIPE request to the I/O target. For more information about resetting a USB pipe, see the USB specification.

The WdfUsbTargetPipeResetSynchronously method does not return until the request has completed, unless the driver supplies a time-out value in the WDF_REQUEST_SEND_OPTIONS structure that the RequestOptions parameter points to, or unless an error is detected.

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 WdfUsbTargetPipeResetSynchronously method's Request parameter.

To create and send a new request, either supply a NULL request handle for the Request parameter, or create a new request object and supply its handle:

• If you supply a NULL request handle, the framework uses an internal request object. This technique is simple to use, but the driver cannot cancel the request.
• If you call WdfRequestCreate to create one or more request objects, you can reuse these request objects by calling WdfRequestReuse. This technique enables your driver's EvtDriverDeviceAdd callback function to preallocate request objects for a device. Additionally, another driver thread can call WdfRequestCancelSentRequest to cancel the request, if necessary.

Your driver can specify a non-NULL RequestOptions parameter, whether the driver provides a non-NULL or a NULL Request parameter. You can, for example, use the RequestOptions parameter to specify a time-out value.

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

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

Examples

The following code example sends a reset request to a USB device's pipe.

NTSTATUS  status;

status = WdfUsbTargetPipeResetSynchronously(
                                            Pipe,
                                            WDF_NO_HANDLE,
                                            NULL
                                            );

See also

WdfObjectDereference

WdfRequestCancelSentRequest

WdfRequestSend

WdfUsbTargetPipeAbortSynchronously