void serial_interrupt(int irq, void *dev_id)
{
    ...

  // Need to loop through each port to see which port caused the interrupt.
  list_for_each(lpNode, &serial_ports)
  {
    struct serial_port_module *ser_dev = list_entry(lpNode, struct serial_port_module, port_list);

    lnIsr = ioread8(ser_dev->membase + ser_dev->chan_num * PORT_OFFSET + SERIAL_ISR);

     if (lnIsr & IPM512_RX_INT)
      {
        while (serialdata_is_data_available(ser_dev)) // equals a ioread8()
        {
          lcIn = ioread8(ser_dev->membase + ser_dev->chan_num * PORT_OFFSET + SERIAL_RBR);

          kfifo_in(&ser_dev->rx_fifo, &lcIn, sizeof(lcIn));

          // Notify if anyone is doing a blocking read.
          wake_up_interruptible(&ser_dev->read_queue);
        }
      }
    }
  }