diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index e3ed70a24029..585a40cc6470 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -2044,6 +2044,10 @@ mlxsw_sp_port_set_link_ksettings(struct net_device *dev,
 	mlxsw_reg_ptys_unpack(ptys_pl, &eth_proto_cap, NULL, NULL);
 
 	autoneg = cmd->base.autoneg == AUTONEG_ENABLE;
+	if (!autoneg && cmd->base.speed == SPEED_56000) {
+		netdev_err(dev, "56G not supported with autoneg off\n");
+		return -EINVAL;
+	}
 	eth_proto_new = autoneg ?
 		mlxsw_sp_to_ptys_advert_link(cmd) :
 		mlxsw_sp_to_ptys_speed(cmd->base.speed);