net: dsa: mv88e6xxx: unlock DSA and CPU ports

BugLink: https://bugs.launchpad.net/bugs/1878232

commit 65fa4027 upstream.

Locking a port generates an hardware interrupt when a new SA address is
received. This enables CPU directed learning, which is needed for 802.1X
MAC authentication.

To disable automatic learning on a port, the only configuration needed
is to set its Port Association Vector to all zero.

Clear PAV when SA learning should be disabled instead of locking a port.

Fixes: 4c7ea3c0 ("net: dsa: mv88e6xxx: disable SA learning for DSA and CPU ports")
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ian May <ian.may@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/net/dsa/mv88e6xxx.c

@@ -2066,7 +2066,7 @@ static int mv88e6xxx_setup_port(struct dsa_switch *ds, int 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;
+		reg = 0;
 
 	ret = _mv88e6xxx_reg_write(ds, REG_PORT(port), PORT_ASSOC_VECTOR, reg);
 	if (ret)