WdfUsbTargetDeviceSendUrbSynchronously function

Description

[Applies to KMDF only]

The WdfUsbTargetDeviceSendUrbSynchronously method sends a USB request synchronously to a specified USB device, using request parameters that are described by a URB.

Parameters

UsbDevice [in]

A handle to a USB device object that was obtained from a previous call to WdfUsbTargetDeviceCreateWithParameters.

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.

Urb [in]

A pointer to a caller-initialized URB structure.

If the driver previously called WdfUsbTargetDeviceCreateWithParameters to create UsbDevice, the driver must use WdfUsbTargetDeviceCreateUrb or WdfUsbTargetDeviceCreateIsochUrb to create this URB.

Return value

WdfUsbTargetDeviceSendUrbSynchronously 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 the WdfUsbTargetDeviceSendUrbSynchronously method to send a USB control transfer request synchronously. To send such requests asynchronously, use WdfUsbTargetDeviceFormatRequestForUrb, followed by WdfRequestSend.

The WdfUsbTargetDeviceSendUrbSynchronously method does not return until the request has completed, unless the driver supplies a time-out value in the RequestOptions parameter's WDF_REQUEST_SEND_OPTIONS structure, 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 WdfUsbTargetDeviceSendUrbSynchronously 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 WdfUsbTargetDeviceSendUrbSynchronously method and USB I/O targets, see USB I/O Targets.

Examples

The following code example initializes a URB structure and calls WdfUsbTargetDeviceSendUrbSynchronously.

URB Urb;
NTSTATUS status;

Urb.UrbHeader.Function =  URB_FUNCTION_GET_CONFIGURATION;
Urb.UrbHeader.Length = sizeof(struct _URB_CONTROL_GET_CONFIGURATION_REQUEST);
Urb.UrbControlGetConfigurationRequest.TransferBufferLength = 1 ; // Must be 1
Urb.UrbControlGetConfigurationRequest.TransferBufferMDL = NULL;
Urb.UrbControlGetConfigurationRequest.TransferBuffer = outBuffer;
Urb.UrbControlGetConfigurationRequest.UrbLink = NULL;

status = WdfUsbTargetDeviceSendUrbSynchronously(
                                                UsbDevice,
                                                NULL,
                                                NULL,
                                                &Urb
                                                );

See also

EvtDriverDeviceAdd

WDF_REQUEST_SEND_OPTIONS

WdfRequestCancelSentRequest

WdfRequestCreate

WdfRequestReuse

WdfRequestSend

WdfUsbTargetDeviceFormatRequestForUrb