diff --git a/drivers/serial/ioc4_serial.c b/drivers/serial/ioc4_serial.c
index c620209..717e47b 100644
--- a/drivers/serial/ioc4_serial.c
+++ b/drivers/serial/ioc4_serial.c
@@ -2646,7 +2646,10 @@
 	struct ioc4_port *port;
 	struct ioc4_soft *soft;
 
+	/* If serial driver did not attach, don't try to detach */
 	control = idd->idd_serial_data;
+	if (!control)
+		return 0;
 
 	for (port_num = 0; port_num < IOC4_NUM_SERIAL_PORTS; port_num++) {
 		for (port_type = UART_PORT_MIN;
@@ -2778,6 +2781,12 @@
 	DPRINT_CONFIG(("%s (0x%p, 0x%p)\n", __FUNCTION__, idd->idd_pdev,
 							idd->idd_pci_id));
 
+	/* PCI-RT does not bring out serial connections.
+	 * Do not attach to this particular IOC4.
+	 */
+	if (idd->idd_variant == IOC4_VARIANT_PCI_RT)
+		return 0;
+
 	/* request serial registers */
 	tmp_addr1 = idd->idd_bar0 + IOC4_SERIAL_OFFSET;