net: dsa: mv88e6xxx: Set PTP Ethertype

For the 6352 and newer switches, the PTP Ethertype defaults to
ETH_P_1588. Hence it was not explicitly set. The 6165 however defaults
to 0. So explicitly set the EtherType.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/hwtstamp.c

@@ -606,6 +606,11 @@ int mv88e6xxx_hwtstamp_setup(struct mv88e6xxx_chip *chip)
 			return err;
 	}
 
+	/* Set the ethertype of L2 PTP messages */
+	err = mv88e6xxx_ptp_write(chip, MV88E6XXX_PTP_GC_ETYPE, ETH_P_1588);
+	if (err)
+		return err;
+
 	/* MV88E6XXX_PTP_MSG_TYPE is a mask of PTP message types to
 	 * timestamp. This affects all ports that have timestamping enabled,
 	 * but the timestamp config is per-port; thus we configure all events

drivers/net/dsa/mv88e6xxx/ptp.h

@@ -82,6 +82,9 @@
 #define MV88E6XXX_PTP_GC_ETYPE			0x00
 
 /* 6165 Global Control Registers */
+/* Offset 0x00: Ether Type */
+#define MV88E6XXX_PTP_GC_ETYPE			0x00
+
 /* Offset 0x01: Message ID */
 #define MV88E6XXX_PTP_GC_MESSAGE_ID		0x01