net: dsa: mv88e6xxx: Don't force link when using in-band-status

When a port is configured with 'managed = "in-band-status"' switch chips
like the 88E6390 need to propagate the SERDES link state to the MAC
because the link state is not correctly detected. This causes problems
on the 88E6185/88E6097 where the link partner won't see link state
changes because we're forcing the link.

To address this introduce a new device specific op port_sync_link() and
push the logic from mv88e6xxx_mac_link_up() into that. Provide an
implementation for the 88E6185 like devices which doesn't force the
link.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/mv88e6xxx/chip.h

@@ -417,6 +417,10 @@ struct mv88e6xxx_ops {
 	 */
 	int (*port_set_link)(struct mv88e6xxx_chip *chip, int port, int link);
 
+	/* Synchronise the port link state with that of the SERDES
+	 */
+	int (*port_sync_link)(struct mv88e6xxx_chip *chip, int port, unsigned int mode, bool isup);
+
 #define PAUSE_ON		1
 #define PAUSE_OFF		0
 

drivers/net/dsa/mv88e6xxx/port.c

@@ -162,6 +162,42 @@ int mv88e6xxx_port_set_link(struct mv88e6xxx_chip *chip, int port, int link)
 	return 0;
 }
 
+int mv88e6xxx_port_sync_link(struct mv88e6xxx_chip *chip, int port, unsigned int mode, bool isup)
+{
+	const struct mv88e6xxx_ops *ops = chip->info->ops;
+	int err = 0;
+	int link;
+
+	if (isup)
+		link = LINK_FORCED_UP;
+	else
+		link = LINK_FORCED_DOWN;
+
+	if (ops->port_set_link)
+		err = ops->port_set_link(chip, port, link);
+
+	return err;
+}
+
+int mv88e6185_port_sync_link(struct mv88e6xxx_chip *chip, int port, unsigned int mode, bool isup)
+{
+	const struct mv88e6xxx_ops *ops = chip->info->ops;
+	int err = 0;
+	int link;
+
+	if (mode == MLO_AN_INBAND)
+		link = LINK_UNFORCED;
+	else if (isup)
+		link = LINK_FORCED_UP;
+	else
+		link = LINK_FORCED_DOWN;
+
+	if (ops->port_set_link)
+		err = ops->port_set_link(chip, port, link);
+
+	return err;
+}
+
 static int mv88e6xxx_port_set_speed_duplex(struct mv88e6xxx_chip *chip,
 					   int port, int speed, bool alt_bit,
 					   bool force_bit, int duplex)

drivers/net/dsa/mv88e6xxx/port.h

@@ -298,6 +298,9 @@ int mv88e6390_port_set_rgmii_delay(struct mv88e6xxx_chip *chip, int port,
 
 int mv88e6xxx_port_set_link(struct mv88e6xxx_chip *chip, int port, int link);
 
+int mv88e6xxx_port_sync_link(struct mv88e6xxx_chip *chip, int port, unsigned int mode, bool isup);
+int mv88e6185_port_sync_link(struct mv88e6xxx_chip *chip, int port, unsigned int mode, bool isup);
+
 int mv88e6065_port_set_speed_duplex(struct mv88e6xxx_chip *chip, int port,
 				    int speed, int duplex);
 int mv88e6185_port_set_speed_duplex(struct mv88e6xxx_chip *chip, int port,