IB/mlx5: When not in dual port RoCE mode, use provided port as native

The series that introduced dual port RoCE mode assumed that we don't have
a dual port HCA that use the mlx5 driver, this is not the case for
Connect-IB HCAs. This reasoning led to assigning 1 as the native port
index which causes issue when the second port is used.

For example query_pkey() when called on the second port will return values
of the first port. Make sure that we assign the right port index as the
native port index.

Fixes: 32f69e4b ("{net, IB}/mlx5: Manage port association for multiport RoCE")
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/main.c

@@ -245,12 +245,16 @@ struct mlx5_core_dev *mlx5_ib_get_native_port_mdev(struct mlx5_ib_dev *ibdev,
 	struct mlx5_ib_multiport_info *mpi;
 	struct mlx5_ib_port *port;
 
+	if (!mlx5_core_mp_enabled(ibdev->mdev) ||
+	    ll != IB_LINK_LAYER_ETHERNET) {
+		if (native_port_num)
+			*native_port_num = ib_port_num;
+		return ibdev->mdev;
+	}
+
 	if (native_port_num)
 		*native_port_num = 1;
 
-	if (!mlx5_core_mp_enabled(ibdev->mdev) || ll != IB_LINK_LAYER_ETHERNET)
-		return ibdev->mdev;
-
 	port = &ibdev->port[ib_port_num - 1];
 	if (!port)
 		return NULL;