Subject: [PATCH net-next v14 3/6] net: dsa: mv88e6xxx: Change serdes lane parameter type from u8 type to int

From: Marek Behún <[email-masked]>
Date: Mon, 11 Jan 2021 02:21:53 +0100

From: Pavana Sharma <[email-masked]>

Returning 0 is no more an error case with MV88E6393 family
which has serdes lane numbers 0, 9 or 10.
So with this change .serdes_get_lane will return lane number
or -errno (-ENODEV or -EOPNOTSUPP).

Signed-off-by: Pavana Sharma <[email-masked]>
Reviewed-by: Andrew Lunn <[email-masked]>
Reviewed-by: Marek Behún <[email-masked]>
---
 drivers/net/dsa/mv88e6xxx/chip.c   | 28 +++++-----
 drivers/net/dsa/mv88e6xxx/chip.h   | 16 +++---
 drivers/net/dsa/mv88e6xxx/port.c   |  8 +--
 drivers/net/dsa/mv88e6xxx/serdes.c | 82 +++++++++++++++---------------
 drivers/net/dsa/mv88e6xxx/serdes.h | 64 +++++++++++------------
 5 files changed, 99 insertions(+), 99 deletions(-)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index eafe6bedc692..9bddd70449c6 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -485,12 +485,12 @@ static int mv88e6xxx_serdes_pcs_get_state(struct dsa_switch *ds, int port,
 					  struct phylink_link_state *state)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
-	u8 lane;
+	int lane;
 	int err;
 
 	mv88e6xxx_reg_lock(chip);
 	lane = mv88e6xxx_serdes_get_lane(chip, port);
-	if (lane && chip->info->ops->serdes_pcs_get_state)
+	if (lane >= 0 && chip->info->ops->serdes_pcs_get_state)
 		err = chip->info->ops->serdes_pcs_get_state(chip, port, lane,
 							    state);
 	else
@@ -506,11 +506,11 @@ static int mv88e6xxx_serdes_pcs_config(struct mv88e6xxx_chip *chip, int port,
 				       const unsigned long *advertise)
 {
 	const struct mv88e6xxx_ops *ops = chip->info->ops;
-	u8 lane;
+	int lane;
 
 	if (ops->serdes_pcs_config) {
 		lane = mv88e6xxx_serdes_get_lane(chip, port);
-		if (lane)
+		if (lane >= 0)
 			return ops->serdes_pcs_config(chip, port, lane, mode,
 						      interface, advertise);
 	}
@@ -523,14 +523,14 @@ static void mv88e6xxx_serdes_pcs_an_restart(struct dsa_switch *ds, int port)
 	struct mv88e6xxx_chip *chip = ds->priv;
 	const struct mv88e6xxx_ops *ops;
 	int err = 0;
-	u8 lane;
+	int lane;
 
 	ops = chip->info->ops;
 
 	if (ops->serdes_pcs_an_restart) {
 		mv88e6xxx_reg_lock(chip);
 		lane = mv88e6xxx_serdes_get_lane(chip, port);
-		if (lane)
+		if (lane >= 0)
 			err = ops->serdes_pcs_an_restart(chip, port, lane);
 		mv88e6xxx_reg_unlock(chip);
 
@@ -544,11 +544,11 @@ static int mv88e6xxx_serdes_pcs_link_up(struct mv88e6xxx_chip *chip, int port,
 					int speed, int duplex)
 {
 	const struct mv88e6xxx_ops *ops = chip->info->ops;
-	u8 lane;
+	int lane;
 
 	if (!phylink_autoneg_inband(mode) && ops->serdes_pcs_link_up) {
 		lane = mv88e6xxx_serdes_get_lane(chip, port);
-		if (lane)
+		if (lane >= 0)
 			return ops->serdes_pcs_link_up(chip, port, lane,
 						       speed, duplex);
 	}
@@ -2431,11 +2431,11 @@ static irqreturn_t mv88e6xxx_serdes_irq_thread_fn(int irq, void *dev_id)
 	struct mv88e6xxx_chip *chip = mvp->chip;
 	irqreturn_t ret = IRQ_NONE;
 	int port = mvp->port;
-	u8 lane;
+	int lane;
 
 	mv88e6xxx_reg_lock(chip);
 	lane = mv88e6xxx_serdes_get_lane(chip, port);
-	if (lane)
+	if (lane >= 0)
 		ret = mv88e6xxx_serdes_irq_status(chip, port, lane);
 	mv88e6xxx_reg_unlock(chip);
 
@@ -2443,7 +2443,7 @@ static irqreturn_t mv88e6xxx_serdes_irq_thread_fn(int irq, void *dev_id)
 }
 
 static int mv88e6xxx_serdes_irq_request(struct mv88e6xxx_chip *chip, int port,
-					u8 lane)
+					int lane)
 {
 	struct mv88e6xxx_port *dev_id = &chip->ports[port];
 	unsigned int irq;
@@ -2472,7 +2472,7 @@ static int mv88e6xxx_serdes_irq_request(struct mv88e6xxx_chip *chip, int port,
 }
 
 static int mv88e6xxx_serdes_irq_free(struct mv88e6xxx_chip *chip, int port,
-				     u8 lane)
+				     int lane)
 {
 	struct mv88e6xxx_port *dev_id = &chip->ports[port];
 	unsigned int irq = dev_id->serdes_irq;
@@ -2497,11 +2497,11 @@ static int mv88e6xxx_serdes_irq_free(struct mv88e6xxx_chip *chip, int port,
 static int mv88e6xxx_serdes_power(struct mv88e6xxx_chip *chip, int port,
 				  bool on)
 {
-	u8 lane;
+	int lane;
 	int err;
 
 	lane = mv88e6xxx_serdes_get_lane(chip, port);
-	if (!lane)
+	if (lane < 0)
 		return 0;
 
 	if (on) {
diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h
index 3543055bcb51..1ac8338d2256 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.h
+++ b/drivers/net/dsa/mv88e6xxx/chip.h
@@ -511,30 +511,30 @@ struct mv88e6xxx_ops {
 	int (*mgmt_rsvd2cpu)(struct mv88e6xxx_chip *chip);
 
 	/* Power on/off a SERDES interface */
-	int (*serdes_power)(struct mv88e6xxx_chip *chip, int port, u8 lane,
+	int (*serdes_power)(struct mv88e6xxx_chip *chip, int port, int lane,
 			    bool up);
 
 	/* SERDES lane mapping */
-	u8 (*serdes_get_lane)(struct mv88e6xxx_chip *chip, int port);
+	int (*serdes_get_lane)(struct mv88e6xxx_chip *chip, int port);
 
 	int (*serdes_pcs_get_state)(struct mv88e6xxx_chip *chip, int port,
-				    u8 lane, struct phylink_link_state *state);
+				    int lane, struct phylink_link_state *state);
 	int (*serdes_pcs_config)(struct mv88e6xxx_chip *chip, int port,
-				 u8 lane, unsigned int mode,
+				 int lane, unsigned int mode,
 				 phy_interface_t interface,
 				 const unsigned long *advertise);
 	int (*serdes_pcs_an_restart)(struct mv88e6xxx_chip *chip, int port,
-				     u8 lane);
+				     int lane);
 	int (*serdes_pcs_link_up)(struct mv88e6xxx_chip *chip, int port,
-				  u8 lane, int speed, int duplex);
+				  int lane, int speed, int duplex);
 
 	/* SERDES interrupt handling */
 	unsigned int (*serdes_irq_mapping)(struct mv88e6xxx_chip *chip,
 					   int port);
-	int (*serdes_irq_enable)(struct mv88e6xxx_chip *chip, int port, u8 lane,
+	int (*serdes_irq_enable)(struct mv88e6xxx_chip *chip, int port, int lane,
 				 bool enable);
 	irqreturn_t (*serdes_irq_status)(struct mv88e6xxx_chip *chip, int port,
-					 u8 lane);
+					 int lane);
 
 	/* Statistics from the SERDES interface */
 	int (*serdes_get_sset_count)(struct mv88e6xxx_chip *chip, int port);
diff --git a/drivers/net/dsa/mv88e6xxx/port.c b/drivers/net/dsa/mv88e6xxx/port.c
index 77a5fd1798cd..0af596957b97 100644
--- a/drivers/net/dsa/mv88e6xxx/port.c
+++ b/drivers/net/dsa/mv88e6xxx/port.c
@@ -429,8 +429,8 @@ phy_interface_t mv88e6390x_port_max_speed_mode(int port)
 static int mv88e6xxx_port_set_cmode(struct mv88e6xxx_chip *chip, int port,
 				    phy_interface_t mode, bool force)
 {
-	u8 lane;
 	u16 cmode;
+	int lane;
 	u16 reg;
 	int err;
 
@@ -466,7 +466,7 @@ static int mv88e6xxx_port_set_cmode(struct mv88e6xxx_chip *chip, int port,
 		return 0;
 
 	lane = mv88e6xxx_serdes_get_lane(chip, port);
-	if (lane) {
+	if (lane >= 0) {
 		if (chip->ports[port].serdes_irq) {
 			err = mv88e6xxx_serdes_irq_disable(chip, port, lane);
 			if (err)
@@ -495,8 +495,8 @@ static int mv88e6xxx_port_set_cmode(struct mv88e6xxx_chip *chip, int port,
 		chip->ports[port].cmode = cmode;
 
 		lane = mv88e6xxx_serdes_get_lane(chip, port);
-		if (!lane)
-			return -ENODEV;
+		if (lane < 0)
+			return lane;
 
 		err = mv88e6xxx_serdes_power_up(chip, port, lane);
 		if (err)
diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
index 3195936dc5be..e48260c5c6ba 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -95,7 +95,7 @@ static int mv88e6xxx_serdes_pcs_get_state(struct mv88e6xxx_chip *chip,
 	return 0;
 }
 
-int mv88e6352_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
+int mv88e6352_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 			   bool up)
 {
 	u16 val, new_val;
@@ -117,7 +117,7 @@ int mv88e6352_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
 }
 
 int mv88e6352_serdes_pcs_config(struct mv88e6xxx_chip *chip, int port,
-				u8 lane, unsigned int mode,
+				int lane, unsigned int mode,
 				phy_interface_t interface,
 				const unsigned long *advertise)
 {
@@ -166,7 +166,7 @@ int mv88e6352_serdes_pcs_config(struct mv88e6xxx_chip *chip, int port,
 }
 
 int mv88e6352_serdes_pcs_get_state(struct mv88e6xxx_chip *chip, int port,
-				   u8 lane, struct phylink_link_state *state)
+				   int lane, struct phylink_link_state *state)
 {
 	u16 lpa, status;
 	int err;
@@ -187,7 +187,7 @@ int mv88e6352_serdes_pcs_get_state(struct mv88e6xxx_chip *chip, int port,
 }
 
 int mv88e6352_serdes_pcs_an_restart(struct mv88e6xxx_chip *chip, int port,
-				    u8 lane)
+				    int lane)
 {
 	u16 bmcr;
 	int err;
@@ -200,7 +200,7 @@ int mv88e6352_serdes_pcs_an_restart(struct mv88e6xxx_chip *chip, int port,
 }
 
 int mv88e6352_serdes_pcs_link_up(struct mv88e6xxx_chip *chip, int port,
-				 u8 lane, int speed, int duplex)
+				 int lane, int speed, int duplex)
 {
 	u16 val, bmcr;
 	int err;
@@ -230,10 +230,10 @@ int mv88e6352_serdes_pcs_link_up(struct mv88e6xxx_chip *chip, int port,
 	return mv88e6352_serdes_write(chip, MII_BMCR, bmcr);
 }
 
-u8 mv88e6352_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
+int mv88e6352_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 {
 	u8 cmode = chip->ports[port].cmode;
-	u8 lane = 0;
+	int lane = -ENODEV;
 
 	if ((cmode == MV88E6XXX_PORT_STS_CMODE_100BASEX) ||
 	    (cmode == MV88E6XXX_PORT_STS_CMODE_1000BASEX) ||
@@ -245,7 +245,7 @@ u8 mv88e6352_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 
 static bool mv88e6352_port_has_serdes(struct mv88e6xxx_chip *chip, int port)
 {
-	if (mv88e6xxx_serdes_get_lane(chip, port))
+	if (mv88e6xxx_serdes_get_lane(chip, port) >= 0)
 		return true;
 
 	return false;
@@ -354,7 +354,7 @@ static void mv88e6352_serdes_irq_link(struct mv88e6xxx_chip *chip, int port)
 }
 
 irqreturn_t mv88e6352_serdes_irq_status(struct mv88e6xxx_chip *chip, int port,
-					u8 lane)
+					int lane)
 {
 	irqreturn_t ret = IRQ_NONE;
 	u16 status;
@@ -372,7 +372,7 @@ irqreturn_t mv88e6352_serdes_irq_status(struct mv88e6xxx_chip *chip, int port,
 	return ret;
 }
 
-int mv88e6352_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, u8 lane,
+int mv88e6352_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, int lane,
 				bool enable)
 {
 	u16 val = 0;
@@ -413,10 +413,10 @@ void mv88e6352_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p)
 	}
 }
 
-u8 mv88e6341_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
+int mv88e6341_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 {
 	u8 cmode = chip->ports[port].cmode;
-	u8 lane = 0;
+	int lane = -ENODEV;
 
 	switch (port) {
 	case 5:
@@ -430,7 +430,7 @@ u8 mv88e6341_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 	return lane;
 }
 
-int mv88e6185_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
+int mv88e6185_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 			   bool up)
 {
 	/* The serdes power can't be controlled on this switch chip but we need
@@ -440,7 +440,7 @@ int mv88e6185_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
 	return 0;
 }
 
-u8 mv88e6185_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
+int mv88e6185_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 {
 	/* There are no configurable serdes lanes on this switch chip but we
 	 * need to return non-zero so that callers of
@@ -456,7 +456,7 @@ u8 mv88e6185_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 }
 
 int mv88e6185_serdes_pcs_get_state(struct mv88e6xxx_chip *chip, int port,
-				   u8 lane, struct phylink_link_state *state)
+				   int lane, struct phylink_link_state *state)
 {
 	int err;
 	u16 status;
@@ -492,7 +492,7 @@ int mv88e6185_serdes_pcs_get_state(struct mv88e6xxx_chip *chip, int port,
 	return 0;
 }
 
-int mv88e6097_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, u8 lane,
+int mv88e6097_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, int lane,
 				bool enable)
 {
 	u8 cmode = chip->ports[port].cmode;
@@ -525,7 +525,7 @@ static void mv88e6097_serdes_irq_link(struct mv88e6xxx_chip *chip, int port)
 }
 
 irqreturn_t mv88e6097_serdes_irq_status(struct mv88e6xxx_chip *chip, int port,
-					u8 lane)
+					int lane)
 {
 	u8 cmode = chip->ports[port].cmode;
 
@@ -539,10 +539,10 @@ irqreturn_t mv88e6097_serdes_irq_status(struct mv88e6xxx_chip *chip, int port,
 	return IRQ_NONE;
 }
 
-u8 mv88e6390_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
+int mv88e6390_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 {
 	u8 cmode = chip->ports[port].cmode;
-	u8 lane = 0;
+	int lane = -ENODEV;
 
 	switch (port) {
 	case 9:
@@ -562,12 +562,12 @@ u8 mv88e6390_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 	return lane;
 }
 
-u8 mv88e6390x_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
+int mv88e6390x_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 {
 	u8 cmode_port = chip->ports[port].cmode;
 	u8 cmode_port10 = chip->ports[10].cmode;
 	u8 cmode_port9 = chip->ports[9].cmode;
-	u8 lane = 0;
+	int lane = -ENODEV;
 
 	switch (port) {
 	case 2:
@@ -638,7 +638,7 @@ u8 mv88e6390x_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 }
 
 /* Set power up/down for 10GBASE-R and 10GBASE-X4/X2 */
-static int mv88e6390_serdes_power_10g(struct mv88e6xxx_chip *chip, u8 lane,
+static int mv88e6390_serdes_power_10g(struct mv88e6xxx_chip *chip, int lane,
 				      bool up)
 {
 	u16 val, new_val;
@@ -665,7 +665,7 @@ static int mv88e6390_serdes_power_10g(struct mv88e6xxx_chip *chip, u8 lane,
 }
 
 /* Set power up/down for SGMII and 1000Base-X */
-static int mv88e6390_serdes_power_sgmii(struct mv88e6xxx_chip *chip, u8 lane,
+static int mv88e6390_serdes_power_sgmii(struct mv88e6xxx_chip *chip, int lane,
 					bool up)
 {
 	u16 val, new_val;
@@ -701,7 +701,7 @@ static struct mv88e6390_serdes_hw_stat mv88e6390_serdes_hw_stats[] = {
 
 int mv88e6390_serdes_get_sset_count(struct mv88e6xxx_chip *chip, int port)
 {
-	if (mv88e6390_serdes_get_lane(chip, port) == 0)
+	if (mv88e6390_serdes_get_lane(chip, port) < 0)
 		return 0;
 
 	return ARRAY_SIZE(mv88e6390_serdes_hw_stats);
@@ -713,7 +713,7 @@ int mv88e6390_serdes_get_strings(struct mv88e6xxx_chip *chip,
 	struct mv88e6390_serdes_hw_stat *stat;
 	int i;
 
-	if (mv88e6390_serdes_get_lane(chip, port) == 0)
+	if (mv88e6390_serdes_get_lane(chip, port) < 0)
 		return 0;
 
 	for (i = 0; i < ARRAY_SIZE(mv88e6390_serdes_hw_stats); i++) {
@@ -750,7 +750,7 @@ int mv88e6390_serdes_get_stats(struct mv88e6xxx_chip *chip, int port,
 	int i;
 
 	lane = mv88e6390_serdes_get_lane(chip, port);
-	if (lane == 0)
+	if (lane < 0)
 		return 0;
 
 	for (i = 0; i < ARRAY_SIZE(mv88e6390_serdes_hw_stats); i++) {
@@ -761,7 +761,7 @@ int mv88e6390_serdes_get_stats(struct mv88e6xxx_chip *chip, int port,
 	return ARRAY_SIZE(mv88e6390_serdes_hw_stats);
 }
 
-static int mv88e6390_serdes_enable_checker(struct mv88e6xxx_chip *chip, u8 lane)
+static int mv88e6390_serdes_enable_checker(struct mv88e6xxx_chip *chip, int lane)
 {
 	u16 reg;
 	int err;
@@ -776,7 +776,7 @@ static int mv88e6390_serdes_enable_checker(struct mv88e6xxx_chip *chip, u8 lane)
 				      MV88E6390_PG_CONTROL, reg);
 }
 
-int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
+int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 			   bool up)
 {
 	u8 cmode = chip->ports[port].cmode;
@@ -801,7 +801,7 @@ int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
 }
 
 int mv88e6390_serdes_pcs_config(struct mv88e6xxx_chip *chip, int port,
-				u8 lane, unsigned int mode,
+				int lane, unsigned int mode,
 				phy_interface_t interface,
 				const unsigned long *advertise)
 {
@@ -860,7 +860,7 @@ int mv88e6390_serdes_pcs_config(struct mv88e6xxx_chip *chip, int port,
 }
 
 static int mv88e6390_serdes_pcs_get_state_sgmii(struct mv88e6xxx_chip *chip,
-	int port, u8 lane, struct phylink_link_state *state)
+	int port, int lane, struct phylink_link_state *state)
 {
 	u16 lpa, status;
 	int err;
@@ -883,7 +883,7 @@ static int mv88e6390_serdes_pcs_get_state_sgmii(struct mv88e6xxx_chip *chip,
 }
 
 static int mv88e6390_serdes_pcs_get_state_10g(struct mv88e6xxx_chip *chip,
-	int port, u8 lane, struct phylink_link_state *state)
+	int port, int lane, struct phylink_link_state *state)
 {
 	u16 status;
 	int err;
@@ -903,7 +903,7 @@ static int mv88e6390_serdes_pcs_get_state_10g(struct mv88e6xxx_chip *chip,
 }
 
 int mv88e6390_serdes_pcs_get_state(struct mv88e6xxx_chip *chip, int port,
-				   u8 lane, struct phylink_link_state *state)
+				   int lane, struct phylink_link_state *state)
 {
 	switch (state->interface) {
 	case PHY_INTERFACE_MODE_SGMII:
@@ -922,7 +922,7 @@ int mv88e6390_serdes_pcs_get_state(struct mv88e6xxx_chip *chip, int port,
 }
 
 int mv88e6390_serdes_pcs_an_restart(struct mv88e6xxx_chip *chip, int port,
-				    u8 lane)
+				    int lane)
 {
 	u16 bmcr;
 	int err;
@@ -938,7 +938,7 @@ int mv88e6390_serdes_pcs_an_restart(struct mv88e6xxx_chip *chip, int port,
 }
 
 int mv88e6390_serdes_pcs_link_up(struct mv88e6xxx_chip *chip, int port,
-				 u8 lane, int speed, int duplex)
+				 int lane, int speed, int duplex)
 {
 	u16 val, bmcr;
 	int err;
@@ -972,7 +972,7 @@ int mv88e6390_serdes_pcs_link_up(struct mv88e6xxx_chip *chip, int port,
 }
 
 static void mv88e6390_serdes_irq_link_sgmii(struct mv88e6xxx_chip *chip,
-					    int port, u8 lane)
+					    int port, int lane)
 {
 	u16 bmsr;
 	int err;
@@ -989,7 +989,7 @@ static void mv88e6390_serdes_irq_link_sgmii(struct mv88e6xxx_chip *chip,
 }
 
 static int mv88e6390_serdes_irq_enable_sgmii(struct mv88e6xxx_chip *chip,
-					     u8 lane, bool enable)
+					     int lane, bool enable)
 {
 	u16 val = 0;
 
@@ -1001,7 +1001,7 @@ static int mv88e6390_serdes_irq_enable_sgmii(struct mv88e6xxx_chip *chip,
 				      MV88E6390_SGMII_INT_ENABLE, val);
 }
 
-int mv88e6390_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, u8 lane,
+int mv88e6390_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, int lane,
 				bool enable)
 {
 	u8 cmode = chip->ports[port].cmode;
@@ -1017,7 +1017,7 @@ int mv88e6390_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, u8 lane,
 }
 
 static int mv88e6390_serdes_irq_status_sgmii(struct mv88e6xxx_chip *chip,
-					     u8 lane, u16 *status)
+					     int lane, u16 *status)
 {
 	int err;
 
@@ -1028,7 +1028,7 @@ static int mv88e6390_serdes_irq_status_sgmii(struct mv88e6xxx_chip *chip,
 }
 
 irqreturn_t mv88e6390_serdes_irq_status(struct mv88e6xxx_chip *chip, int port,
-					u8 lane)
+					int lane)
 {
 	u8 cmode = chip->ports[port].cmode;
 	irqreturn_t ret = IRQ_NONE;
@@ -1087,7 +1087,7 @@ static const u16 mv88e6390_serdes_regs[] = {
 
 int mv88e6390_serdes_get_regs_len(struct mv88e6xxx_chip *chip, int port)
 {
-	if (mv88e6xxx_serdes_get_lane(chip, port) == 0)
+	if (mv88e6xxx_serdes_get_lane(chip, port) < 0)
 		return 0;
 
 	return ARRAY_SIZE(mv88e6390_serdes_regs) * sizeof(u16);
@@ -1102,7 +1102,7 @@ void mv88e6390_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p)
 	int i;
 
 	lane = mv88e6xxx_serdes_get_lane(chip, port);
-	if (lane == 0)
+	if (lane < 0)
 		return;
 
 	for (i = 0 ; i < ARRAY_SIZE(mv88e6390_serdes_regs); i++) {
diff --git a/drivers/net/dsa/mv88e6xxx/serdes.h b/drivers/net/dsa/mv88e6xxx/serdes.h
index 93822ef9bab8..ce4d0fef124d 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.h
+++ b/drivers/net/dsa/mv88e6xxx/serdes.h
@@ -73,55 +73,55 @@
 #define MV88E6390_PG_CONTROL		0xf010
 #define MV88E6390_PG_CONTROL_ENABLE_PC		BIT(0)
 
-u8 mv88e6185_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
-u8 mv88e6341_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
-u8 mv88e6352_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
-u8 mv88e6390_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
-u8 mv88e6390x_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
+int mv88e6185_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
+int mv88e6341_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
+int mv88e6352_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
+int mv88e6390_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
+int mv88e6390x_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
 int mv88e6352_serdes_pcs_config(struct mv88e6xxx_chip *chip, int port,
-				u8 lane, unsigned int mode,
+				int lane, unsigned int mode,
 				phy_interface_t interface,
 				const unsigned long *advertise);
 int mv88e6390_serdes_pcs_config(struct mv88e6xxx_chip *chip, int port,
-				u8 lane, unsigned int mode,
+				int lane, unsigned int mode,
 				phy_interface_t interface,
 				const unsigned long *advertise);
 int mv88e6185_serdes_pcs_get_state(struct mv88e6xxx_chip *chip, int port,
-				   u8 lane, struct phylink_link_state *state);
+				   int lane, struct phylink_link_state *state);
 int mv88e6352_serdes_pcs_get_state(struct mv88e6xxx_chip *chip, int port,
-				   u8 lane, struct phylink_link_state *state);
+				   int lane, struct phylink_link_state *state);
 int mv88e6390_serdes_pcs_get_state(struct mv88e6xxx_chip *chip, int port,
-				   u8 lane, struct phylink_link_state *state);
+				   int lane, struct phylink_link_state *state);
 int mv88e6352_serdes_pcs_an_restart(struct mv88e6xxx_chip *chip, int port,
-				    u8 lane);
+				    int lane);
 int mv88e6390_serdes_pcs_an_restart(struct mv88e6xxx_chip *chip, int port,
-				    u8 lane);
+				    int lane);
 int mv88e6352_serdes_pcs_link_up(struct mv88e6xxx_chip *chip, int port,
-				 u8 lane, int speed, int duplex);
+				 int lane, int speed, int duplex);
 int mv88e6390_serdes_pcs_link_up(struct mv88e6xxx_chip *chip, int port,
-				 u8 lane, int speed, int duplex);
+				 int lane, int speed, int duplex);
 unsigned int mv88e6352_serdes_irq_mapping(struct mv88e6xxx_chip *chip,
 					  int port);
 unsigned int mv88e6390_serdes_irq_mapping(struct mv88e6xxx_chip *chip,
 					  int port);
-int mv88e6185_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
+int mv88e6185_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 			   bool up);
-int mv88e6352_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
+int mv88e6352_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 			   bool on);
-int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
+int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 			   bool on);
-int mv88e6097_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, u8 lane,
+int mv88e6097_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, int lane,
 				bool enable);
-int mv88e6352_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, u8 lane,
+int mv88e6352_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, int lane,
 				bool enable);
-int mv88e6390_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, u8 lane,
+int mv88e6390_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, int lane,
 				bool enable);
 irqreturn_t mv88e6097_serdes_irq_status(struct mv88e6xxx_chip *chip, int port,
-					u8 lane);
+					int lane);
 irqreturn_t mv88e6352_serdes_irq_status(struct mv88e6xxx_chip *chip, int port,
-					u8 lane);
+					int lane);
 irqreturn_t mv88e6390_serdes_irq_status(struct mv88e6xxx_chip *chip, int port,
-					u8 lane);
+					int lane);
 int mv88e6352_serdes_get_sset_count(struct mv88e6xxx_chip *chip, int port);
 int mv88e6352_serdes_get_strings(struct mv88e6xxx_chip *chip,
 				 int port, uint8_t *data);
@@ -138,18 +138,18 @@ void mv88e6352_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p);
 int mv88e6390_serdes_get_regs_len(struct mv88e6xxx_chip *chip, int port);
 void mv88e6390_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p);
 
-/* Return the (first) SERDES lane address a port is using, 0 otherwise. */
-static inline u8 mv88e6xxx_serdes_get_lane(struct mv88e6xxx_chip *chip,
-					   int port)
+/* Return the (first) SERDES lane address a port is using, -errno otherwise. */
+static inline int mv88e6xxx_serdes_get_lane(struct mv88e6xxx_chip *chip,
+					    int port)
 {
 	if (!chip->info->ops->serdes_get_lane)
-		return 0;
+		return -EOPNOTSUPP;
 
 	return chip->info->ops->serdes_get_lane(chip, port);
 }
 
 static inline int mv88e6xxx_serdes_power_up(struct mv88e6xxx_chip *chip,
-					    int port, u8 lane)
+					    int port, int lane)
 {
 	if (!chip->info->ops->serdes_power)
 		return -EOPNOTSUPP;
@@ -158,7 +158,7 @@ static inline int mv88e6xxx_serdes_power_up(struct mv88e6xxx_chip *chip,
 }
 
 static inline int mv88e6xxx_serdes_power_down(struct mv88e6xxx_chip *chip,
-					      int port, u8 lane)
+					      int port, int lane)
 {
 	if (!chip->info->ops->serdes_power)
 		return -EOPNOTSUPP;
@@ -176,7 +176,7 @@ mv88e6xxx_serdes_irq_mapping(struct mv88e6xxx_chip *chip, int port)
 }
 
 static inline int mv88e6xxx_serdes_irq_enable(struct mv88e6xxx_chip *chip,
-					      int port, u8 lane)
+					      int port, int lane)
 {
 	if (!chip->info->ops->serdes_irq_enable)
 		return -EOPNOTSUPP;
@@ -185,7 +185,7 @@ static inline int mv88e6xxx_serdes_irq_enable(struct mv88e6xxx_chip *chip,
 }
 
 static inline int mv88e6xxx_serdes_irq_disable(struct mv88e6xxx_chip *chip,
-					       int port, u8 lane)
+					       int port, int lane)
 {
 	if (!chip->info->ops->serdes_irq_enable)
 		return -EOPNOTSUPP;
@@ -194,7 +194,7 @@ static inline int mv88e6xxx_serdes_irq_disable(struct mv88e6xxx_chip *chip,
 }
 
 static inline irqreturn_t
-mv88e6xxx_serdes_irq_status(struct mv88e6xxx_chip *chip, int port, u8 lane)
+mv88e6xxx_serdes_irq_status(struct mv88e6xxx_chip *chip, int port, int lane)
 {
 	if (!chip->info->ops->serdes_irq_status)
 		return IRQ_NONE;
-- 
2.26.2