IB/mlx5: Avoid load failure due to unknown link width

commit db7a691a1551a748cb92d9c89c6b190ea87e28d5 upstream.

If the firmware reports a connection width that is not 1x, 4x, 8x or 12x
it causes the driver to fail during initialization.

To prevent this failure every time a new width is introduced to the RDMA
stack, we will set a default 4x width for these widths which ar unknown to
the driver.

This is needed to allow to run old kernels with new firmware.

Cc: <stable@vger.kernel.org> # 4.1
Fixes: 1b5daf11b015 ("IB/mlx5: Avoid using the MAD_IFC command under ISSI > 0 mode")
Signed-off-by: Michael Guralnik <michaelgur@mellanox.com>
Reviewed-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index c3a4f5d..13a9206 100644 (file)
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -869,31 +869,26 @@ enum mlx5_ib_width {
        MLX5_IB_WIDTH_12X       = 1 << 4
 };
 
-static int translate_active_width(struct ib_device *ibdev, u8 active_width,
+static void translate_active_width(struct ib_device *ibdev, u8 active_width,
                                  u8 *ib_width)
 {
        struct mlx5_ib_dev *dev = to_mdev(ibdev);
-       int err = 0;
 
-       if (active_width & MLX5_IB_WIDTH_1X) {
+       if (active_width & MLX5_IB_WIDTH_1X)
                *ib_width = IB_WIDTH_1X;
-       } else if (active_width & MLX5_IB_WIDTH_2X) {
-               mlx5_ib_dbg(dev, "active_width %d is not supported by IB spec\n",
-                           (int)active_width);
-               err = -EINVAL;
-       } else if (active_width & MLX5_IB_WIDTH_4X) {
+       else if (active_width & MLX5_IB_WIDTH_4X)
                *ib_width = IB_WIDTH_4X;
-       } else if (active_width & MLX5_IB_WIDTH_8X) {
+       else if (active_width & MLX5_IB_WIDTH_8X)
                *ib_width = IB_WIDTH_8X;
-       } else if (active_width & MLX5_IB_WIDTH_12X) {
+       else if (active_width & MLX5_IB_WIDTH_12X)
                *ib_width = IB_WIDTH_12X;
-       } else {
-               mlx5_ib_dbg(dev, "Invalid active_width %d\n",
+       else {
+               mlx5_ib_dbg(dev, "Invalid active_width %d, setting width to default value: 4x\n",
                            (int)active_width);
-               err = -EINVAL;
+               *ib_width = IB_WIDTH_4X;
        }
 
-       return err;
+       return;
 }
 
 static int mlx5_mtu_to_ib_mtu(int mtu)
@@ -1001,10 +996,8 @@ static int mlx5_query_hca_port(struct ib_device *ibdev, u8 port,
        if (err)
                goto out;
 
-       err = translate_active_width(ibdev, ib_link_width_oper,
-                                    &props->active_width);
-       if (err)
-               goto out;
+       translate_active_width(ibdev, ib_link_width_oper, &props->active_width);
+
        err = mlx5_query_port_ib_proto_oper(mdev, &props->active_speed, port);
        if (err)
                goto out;