IB/mlx4: Pass congestion management class MADs to the HCA

ConnectX HCAs support the IB_MGMT_CLASS_CONG_MGMT management class, so
process MADs of this class through the MAD_IFC firmware command.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/mlx4/mad.c b/drivers/infiniband/hw/mlx4/mad.c
index 4c1e72f..cdca3a5 100644
--- a/drivers/infiniband/hw/mlx4/mad.c
+++ b/drivers/infiniband/hw/mlx4/mad.c
@@ -255,7 +255,8 @@
 			return IB_MAD_RESULT_SUCCESS;
 	} else if (in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_PERF_MGMT ||
 		   in_mad->mad_hdr.mgmt_class == MLX4_IB_VENDOR_CLASS1   ||
-		   in_mad->mad_hdr.mgmt_class == MLX4_IB_VENDOR_CLASS2) {
+		   in_mad->mad_hdr.mgmt_class == MLX4_IB_VENDOR_CLASS2   ||
+		   in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_CONG_MGMT) {
 		if (in_mad->mad_hdr.method  != IB_MGMT_METHOD_GET &&
 		    in_mad->mad_hdr.method  != IB_MGMT_METHOD_SET)
 			return IB_MAD_RESULT_SUCCESS;