net: dsa: microchip: Disable RGMII in-band status on KSZ9893

We can't assume that the link partner supports the in-band status
reporting which is enabled by default on the KSZ9893 when using RGMII
for the upstream port.
Signed-off-by: NPaul Barker <pbarker@konsulko.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/dsa/microchip/ksz9477.c

@@ -1235,6 +1235,9 @@ static void ksz9477_port_setup(struct ksz_device *dev, int port, bool cpu_port)
 			if (dev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
 			    dev->interface == PHY_INTERFACE_MODE_RGMII_TXID)
 				data8 |= PORT_RGMII_ID_EG_ENABLE;
+			/* On KSZ9893, disable RGMII in-band status support */
+			if (dev->features & IS_9893)
+				data8 &= ~PORT_MII_MAC_MODE;
 			p->phydev.speed = SPEED_1000;
 			break;
 		}