def METHOD_NAME(self):
    """
    Retrieves the speed of the fan
    Returns:
        int: percentage of the max fan speed
    """
    if self.max_speed == 0:
        is_valid, max_speed = self.fru.get_fru_data(self.max_speed_offset,2)
        if not is_valid:
            return 0
        self.max_speed = max_speed[1]
        self.max_speed = max_speed[1] << 8 | max_speed[0]
    is_valid, fan_speed = self.speed_sensor.get_reading()
    if not is_valid or self.max_speed == 0:
        speed = 0
    else:
        speed = (100 * fan_speed)//self.max_speed
    return speed