IWDFUsbTargetPipe::SetPipePolicy method

The SetPipePolicy method sets the WinUsb pipe policy.

Syntax


HRESULT SetPipePolicy(
  [in]  ULONG PolicyType,
  [in]  ULONG ValueLength,
  [in]  PVOID Value
);

Parameters

PolicyType [in]: The type of WinUsb pipe policy that the UMDF driver sets.
ValueLength [in]: The size, in bytes, of the buffer that SetPipePolicy supplies for Value.
Value [in]: A pointer to the buffer that contains the WinUsb pipe policy.

Return value

SetPipePolicy returns one of the following values:

Return code	Description
S_OK	SetPipePolicy successfully set the WinUsb pipe policy.
E_OUTOFMEMORY	SetPipePolicy encountered an allocation failure.
An error code that is defined in Winerror.h	This value corresponds to the error code that the WinUsb API returned.

Remarks

Pipe policy controls the behavior of the USB pipe (for example, time-outs, handling short packets, and so on).

For more information about valid policy types and values that a UMDF driver can pass for the PolicyType and Value parameters, see the WinUsb_SetPipePolicy function.

For information about the behavior of the pipe policies, see WinUSB Functions for Pipe Policy Modification.

The SetPipePolicy method generates a UMDF request and synchronously sends the request to the I/O target.

Examples

The following code example sets policy for input and output pipes.


HRESULT
CMyDevice::ConfigureUsbIoTargets(
    )
{
    HRESULT                 hr;
    USB_INTERFACE_DESCRIPTOR pInterface;
    WINUSB_PIPE_INFORMATION pipe;
    BOOL                    policy;
    DWORD                   err;
    BOOL                    result;
    LONG                    i;
    LONG                    timeout;
    ULONG                   length;

    length = sizeof(UCHAR);
    hr = m_pIUsbTargetDevice->RetrieveDeviceInformation(DEVICE_SPEED, 
                                                        &length,
                                                        &m_Speed);
    if (FAILED(hr)) {
        // Print out error.
    }
    if (SUCCEEDED(hr)) {
        // Print out device speed.
    }
    //
    // Set timeout policies for input and output pipes.
    //
    if (SUCCEEDED(hr))  {
       timeout = ENDPOINT_TIMEOUT;
       hr = m_pIUsbInputPipe->SetPipePolicy(PIPE_TRANSFER_TIMEOUT,
                                            sizeof(timeout),
                                            &timeout);
       if (FAILED(hr)) {
            // Print out cannot set timeout policy for input pipe.
       }
    }
    if (SUCCEEDED(hr))  {
       timeout = ENDPOINT_TIMEOUT;
       hr = m_pIUsbOutputPipe->SetPipePolicy(PIPE_TRANSFER_TIMEOUT,
                                             sizeof(timeout),
                                             &timeout);
       if (FAILED(hr))  {
            // Print out cannot set timeout policy for output pipe.
       }
    }
 return hr;
}

Requirements

End of support	Unavailable in UMDF 2.0 and later.
Minimum UMDF version	1.5
Header	Wudfusb.h (include Wudfusb.h)
DLL	WUDFx.dll