net: dsa: mv88e6xxx: disable SA learning for DSA and CPU ports

Frames with DSA headers passing to/from the CPU were taking place in the
MAC learning on these ports, resulting in incorrect ATU entries. Disable
learning on these ports.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c
index 85228f4..3116990 100644
--- a/drivers/net/dsa/mv88e6xxx.c
+++ b/drivers/net/dsa/mv88e6xxx.c
@@ -2029,8 +2029,12 @@
 	 * a port bitmap that has only the bit for this port set and
 	 * the other bits clear.
 	 */
-	ret = _mv88e6xxx_reg_write(ds, REG_PORT(port), PORT_ASSOC_VECTOR,
-				   1 << port);
+	reg = 1 << port;
+	/* Disable learning for DSA and CPU ports */
+	if (dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port))
+		reg = PORT_ASSOC_VECTOR_LOCKED_PORT;
+
+	ret = _mv88e6xxx_reg_write(ds, REG_PORT(port), PORT_ASSOC_VECTOR, reg);
 	if (ret)
 		goto abort;