diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index be31d85a50e3..4604153b7954 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1052,9 +1052,17 @@ static int sci_request_irq(struct sci_port *port)
 		if (SCIx_IRQ_IS_MUXED(port)) {
 			i = SCIx_MUX_IRQ;
 			irq = up->irq;
-		} else
+		} else {
 			irq = port->cfg->irqs[i];
 
+			/*
+			 * Certain port types won't support all of the
+			 * available interrupt sources.
+			 */
+			if (unlikely(!irq))
+				continue;
+		}
+
 		desc = sci_irq_desc + i;
 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
 					    dev_name(up->dev), desc->desc);
@@ -1094,6 +1102,15 @@ static void sci_free_irq(struct sci_port *port)
 	 * IRQ first.
 	 */
 	for (i = 0; i < SCIx_NR_IRQS; i++) {
+		unsigned int irq = port->cfg->irqs[i];
+
+		/*
+		 * Certain port types won't support all of the available
+		 * interrupt sources.
+		 */
+		if (unlikely(!irq))
+			continue;
+
 		free_irq(port->cfg->irqs[i], port);
 		kfree(port->irqstr[i]);