net: dsa: mv88e6xxx: Configure MAC when using fixed link

The 88e6185 is reporting it has detected a PHY, when a port is
connected to an SFP. As a result, the fixed-phy configuration is not
being applied. That then breaks packet transfer, since the port is
reported as being down.

Add additional conditions to check the interface mode, and if it is
fixed always configure the port on link up/down, independent of the
PPU status.

Fixes: 30c4a5b ("net: mv88e6xxx: use resolved link config in mac_link_up()")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/chip.c

@@ -709,7 +709,8 @@ static void mv88e6xxx_mac_link_down(struct dsa_switch *ds, int port,
 	ops = chip->info->ops;
 
 	mv88e6xxx_reg_lock(chip);
-	if (!mv88e6xxx_port_ppu_updates(chip, port) && ops->port_set_link)
+	if ((!mv88e6xxx_port_ppu_updates(chip, port) ||
+	     mode == MLO_AN_FIXED) && ops->port_set_link)
 		err = ops->port_set_link(chip, port, LINK_FORCED_DOWN);
 	mv88e6xxx_reg_unlock(chip);
 
@@ -731,7 +732,7 @@ static void mv88e6xxx_mac_link_up(struct dsa_switch *ds, int port,
 	ops = chip->info->ops;
 
 	mv88e6xxx_reg_lock(chip);
-	if (!mv88e6xxx_port_ppu_updates(chip, port)) {
+	if (!mv88e6xxx_port_ppu_updates(chip, port) || mode == MLO_AN_FIXED) {
 		/* FIXME: for an automedia port, should we force the link
 		 * down here - what if the link comes up due to "other" media
 		 * while we're bringing the port up, how is the exclusivity