IB/ipath: Fix maximum MTU reporting

Although our chip supports 4K MTUs, our driver doesn't yet support
this feature, so limit the maximum MTU to 2K until we get support for
4K MTUs implemented.

Signed-off-by: Robert Walsh <robert.walsh@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_qp.c b/drivers/infiniband/hw/ipath/ipath_qp.c
index bfef08ecd342..9e07abba8aa7 100644
--- a/drivers/infiniband/hw/ipath/ipath_qp.c
+++ b/drivers/infiniband/hw/ipath/ipath_qp.c
@@ -507,8 +507,13 @@ int ipath_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
                     attr->port_num > ibqp->device->phys_port_cnt)
                         goto inval;
 
+        /*
+         * Note: the chips support a maximum MTU of 4096, but the driver
+         * hasn't implemented this feature yet, so don't allow Path MTU
+         * values greater than 2048.
+         */
         if (attr_mask & IB_QP_PATH_MTU)
-                if (attr->path_mtu > IB_MTU_4096)
+                if (attr->path_mtu > IB_MTU_2048)
                         goto inval;
 
         if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)