4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Heiner Kallweit <hkallweit1@xxxxxxxxx> [ Upstream commit c6195a8bdfc62a7cecf7df685e64847a4b700275 ] When testing another issue I faced the problem that mv88e6xxx_port_setup_mac() failed due to DUPLEX_UNKNOWN being passed as argument to mv88e6xxx_port_set_duplex(). We should handle this case gracefully and return -EOPNOTSUPP, like e.g. mv88e6xxx_port_set_speed() is doing it. Fixes: 7f1ae07b51e8 ("net: dsa: mv88e6xxx: add port duplex setter") Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx> 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 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/dsa/mv88e6xxx/port.c +++ b/drivers/net/dsa/mv88e6xxx/port.c @@ -165,7 +165,7 @@ int mv88e6xxx_port_set_duplex(struct mv8 /* normal duplex detection */ break; default: - return -EINVAL; + return -EOPNOTSUPP; } err = mv88e6xxx_port_write(chip, port, MV88E6XXX_PORT_MAC_CTL, reg);