diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index 91297df4371c..85fb727c13eb 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -909,10 +909,58 @@ static void ksz8_port_mirror_del(struct dsa_switch *ds, int port,
 			     PORT_MIRROR_SNIFFER, false);
 }
 
+static void ksz8795_cpu_interface_select(struct ksz_device *dev, int port)
+{
+	struct ksz_port *p = &dev->ports[port];
+	u8 data8;
+
+	if (!p->interface && dev->compat_interface) {
+		dev_warn(dev->dev,
+			 "Using legacy switch \"phy-mode\" property, because it is missing on port %d node. "
+			 "Please update your device tree.\n",
+			 port);
+		p->interface = dev->compat_interface;
+	}
+
+	/* Configure MII interface for proper network communication. */
+	ksz_read8(dev, REG_PORT_5_CTRL_6, &data8);
+	data8 &= ~PORT_INTERFACE_TYPE;
+	data8 &= ~PORT_GMII_1GPS_MODE;
+	switch (p->interface) {
+	case PHY_INTERFACE_MODE_MII:
+		p->phydev.speed = SPEED_100;
+		break;
+	case PHY_INTERFACE_MODE_RMII:
+		data8 |= PORT_INTERFACE_RMII;
+		p->phydev.speed = SPEED_100;
+		break;
+	case PHY_INTERFACE_MODE_GMII:
+		data8 |= PORT_GMII_1GPS_MODE;
+		data8 |= PORT_INTERFACE_GMII;
+		p->phydev.speed = SPEED_1000;
+		break;
+	default:
+		data8 &= ~PORT_RGMII_ID_IN_ENABLE;
+		data8 &= ~PORT_RGMII_ID_OUT_ENABLE;
+		if (p->interface == PHY_INTERFACE_MODE_RGMII_ID ||
+		    p->interface == PHY_INTERFACE_MODE_RGMII_RXID)
+			data8 |= PORT_RGMII_ID_IN_ENABLE;
+		if (p->interface == PHY_INTERFACE_MODE_RGMII_ID ||
+		    p->interface == PHY_INTERFACE_MODE_RGMII_TXID)
+			data8 |= PORT_RGMII_ID_OUT_ENABLE;
+		data8 |= PORT_GMII_1GPS_MODE;
+		data8 |= PORT_INTERFACE_RGMII;
+		p->phydev.speed = SPEED_1000;
+		break;
+	}
+	ksz_write8(dev, REG_PORT_5_CTRL_6, data8);
+	p->phydev.duplex = 1;
+}
+
 static void ksz8_port_setup(struct ksz_device *dev, int port, bool cpu_port)
 {
 	struct ksz_port *p = &dev->ports[port];
-	u8 data8, member;
+	u8 member;
 
 	/* enable broadcast storm limit */
 	ksz_port_cfg(dev, port, P_BCAST_STORM_CTRL, PORT_BROADCAST_STORM, true);
@@ -929,47 +977,7 @@ static void ksz8_port_setup(struct ksz_device *dev, int port, bool cpu_port)
 	ksz_port_cfg(dev, port, P_PRIO_CTRL, PORT_802_1P_ENABLE, true);
 
 	if (cpu_port) {
-		if (!p->interface && dev->compat_interface) {
-			dev_warn(dev->dev,
-				 "Using legacy switch \"phy-mode\" property, because it is missing on port %d node. "
-				 "Please update your device tree.\n",
-				 port);
-			p->interface = dev->compat_interface;
-		}
-
-		/* Configure MII interface for proper network communication. */
-		ksz_read8(dev, REG_PORT_5_CTRL_6, &data8);
-		data8 &= ~PORT_INTERFACE_TYPE;
-		data8 &= ~PORT_GMII_1GPS_MODE;
-		switch (p->interface) {
-		case PHY_INTERFACE_MODE_MII:
-			p->phydev.speed = SPEED_100;
-			break;
-		case PHY_INTERFACE_MODE_RMII:
-			data8 |= PORT_INTERFACE_RMII;
-			p->phydev.speed = SPEED_100;
-			break;
-		case PHY_INTERFACE_MODE_GMII:
-			data8 |= PORT_GMII_1GPS_MODE;
-			data8 |= PORT_INTERFACE_GMII;
-			p->phydev.speed = SPEED_1000;
-			break;
-		default:
-			data8 &= ~PORT_RGMII_ID_IN_ENABLE;
-			data8 &= ~PORT_RGMII_ID_OUT_ENABLE;
-			if (p->interface == PHY_INTERFACE_MODE_RGMII_ID ||
-			    p->interface == PHY_INTERFACE_MODE_RGMII_RXID)
-				data8 |= PORT_RGMII_ID_IN_ENABLE;
-			if (p->interface == PHY_INTERFACE_MODE_RGMII_ID ||
-			    p->interface == PHY_INTERFACE_MODE_RGMII_TXID)
-				data8 |= PORT_RGMII_ID_OUT_ENABLE;
-			data8 |= PORT_GMII_1GPS_MODE;
-			data8 |= PORT_INTERFACE_RGMII;
-			p->phydev.speed = SPEED_1000;
-			break;
-		}
-		ksz_write8(dev, REG_PORT_5_CTRL_6, data8);
-		p->phydev.duplex = 1;
+		ksz8795_cpu_interface_select(dev, port);
 
 		member = dev->port_mask;
 	} else {