[PATCH 4.20 55/76] net: dsa: mv88e6xxx: power serdes on/off for 10G interfaces on 6390X

[Greg Kroah-Hartman]

4.20-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>

[ Upstream commit d235c48b40d399328585a68f3f9bf7cc3062d586 ]

Upon setting the cmode on 6390 and 6390X, the associated serdes
interfaces must be powered off/on.

Both 6390X and 6390 share code to do so, but it currently uses the 6390
specific helper mv88e6390_serdes_power() to disable and enable the
serdes interface.

This call will fail silently on 6390X when trying so set a 10G interface
such as XAUI or RXAUI, since mv88e6390_serdes_power() internally grabs
the lane number based on modes supported by the 6390, and returns 0 when
getting -ENODEV as a lane number.

Using mv88e6390x_serdes_power() should be safe here, since we explicitly
rule-out all ports but the 9 and 10, and because modes supported by 6390
ports 9 and 10 are a subset of those supported on 6390X.

This was tested on 6390X using RXAUI mode.

Fixes: 364e9d7776a3 ("net: dsa: mv88e6xxx: Power on/off SERDES on cmode change")
Signed-off-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/dsa/mv88e6xxx/port.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/dsa/mv88e6xxx/port.c
+++ b/drivers/net/dsa/mv88e6xxx/port.c
@@ -405,7 +405,7 @@ int mv88e6390x_port_set_cmode(struct mv8
 			return err;
 	}
 
-	err = mv88e6390_serdes_power(chip, port, false);
+	err = mv88e6390x_serdes_power(chip, port, false);
 	if (err)
 		return err;
 
@@ -421,7 +421,7 @@ int mv88e6390x_port_set_cmode(struct mv8
 		if (err)
 			return err;
 
-		err = mv88e6390_serdes_power(chip, port, true);
+		err = mv88e6390x_serdes_power(chip, port, true);
 		if (err)
 			return err;