diff --git a/drivers/tty/serial/8250/8250_men_mcb.c b/drivers/tty/serial/8250/8250_men_mcb.c
index 02c5aff58a74..8df89e9cd254 100644
--- a/drivers/tty/serial/8250/8250_men_mcb.c
+++ b/drivers/tty/serial/8250/8250_men_mcb.c
@@ -72,8 +72,8 @@ static int serial_8250_men_mcb_probe(struct mcb_device *mdev,
 {
 	struct serial_8250_men_mcb_data *data;
 	struct resource *mem;
-	unsigned int num_ports;
-	unsigned int i;
+	int num_ports;
+	int i;
 	void __iomem *membase;
 
 	mem = mcb_get_resource(mdev, IORESOURCE_MEM);
@@ -88,7 +88,7 @@ static int serial_8250_men_mcb_probe(struct mcb_device *mdev,
 	dev_dbg(&mdev->dev, "found a 16z%03u with %u ports\n",
 		mdev->id, num_ports);
 
-	if (num_ports == 0 || num_ports > 4) {
+	if (num_ports <= 0 || num_ports > 4) {
 		dev_err(&mdev->dev, "unexpected number of ports: %u\n",
 			num_ports);
 		return -ENODEV;
@@ -133,7 +133,7 @@ static int serial_8250_men_mcb_probe(struct mcb_device *mdev,
 
 static void serial_8250_men_mcb_remove(struct mcb_device *mdev)
 {
-	unsigned int num_ports, i;
+	int num_ports, i;
 	struct serial_8250_men_mcb_data *data = mcb_get_drvdata(mdev);
 
 	if (!data)