QSerialPortInfo should expose the device serial number

I have started to play with QtSerialPort on Qt 4.8.4.
I noticed that there is no way to uniquely identify a serial interface from the current information provided (portName, description, manufacturer)

I explain. If there are 2 USB FTDI dongles of the same type connnected to the computer, they can be distinguished only by their ttyUSBx name.
Problem is that if an application saves the devices status by ttyUSB name, the next time the dongles are connected they could swap their names, so the application will get confused.

I've been working with libftdi and ftd2xx and they both allow to read the device serial number, which should be unique.

Thanks