IB/mlx4: Don't return an invalid speed when a port is down

When the IB port is down, the active_speed value returned by the
MAD_IFC command is seven (7) which isn't among the defined IB speeds
in enum ib_port_speed, and this invalid speed value is passed up to
higher layers or applications who do port query.

Fix that by setting the speed to be SDR -- the lowest possible -- when
the port is down.

Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index 75d305629300..669673e81439 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -253,6 +253,11 @@ static int ib_link_query_port(struct ib_device *ibdev, u8 port,
                 if (out_mad->data[15] & 0x1)
                         props->active_speed = IB_SPEED_FDR10;
         }
+
+        /* Avoid wrong speed value returned by FW if the IB link is down. */
+        if (props->state == IB_PORT_DOWN)
+                 props->active_speed = IB_SPEED_SDR;
+
 out:
         kfree(in_mad);
         kfree(out_mad);