The IOCTL_UMDF_GET_PHYSICAL_DESCRIPTOR control code obtains the physical descriptor of a HIDClass device.
A UMDF-based driver obtains the size, in bytes, of the buffer by calling IWDFRequest::GetDeviceIoControlParameters and providing the pOutBufferSize parameter.
Input Buffer Length
The driver copies the physical descriptor to the user buffer that is retrieved by calling IWDFIoRequest::GetOutputMemory.
Output Buffer Length
The size of the buffer that is retrieved by calling IWDFIoRequest::GetOutputMemory.
Input / Output Buffer
Input / Output Buffer Length
HID minidrivers that carry out the I/O to the device must also:
- Call IWDFRequest::SetInformation to set the number of bytes transferred from the device.
- Call IWDFRequest::Complete with S_OK to complete the request without error. Otherwise, set the appropriate HRESULT error code.