IB/ehca: Use default value for Local CA ACK Delay if FW returns 0

Some firmware versions report a Local CA ACK Delay of 0.  In that
case, return a more sensible default value of 12 (-> 16 msec) instead.
Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ehca/ehca_hca.c

@@ -114,7 +114,9 @@ int ehca_query_device(struct ib_device *ibdev, struct ib_device_attr *props)
 	}
 
 	props->max_pkeys           = 16;
-	props->local_ca_ack_delay  = min_t(u8, rblock->local_ca_ack_delay, 255);
+	/* Some FW versions say 0 here; insert sensible value in that case */
+	props->local_ca_ack_delay  = rblock->local_ca_ack_delay ?
+		min_t(u8, rblock->local_ca_ack_delay, 255) : 12;
 	props->max_raw_ipv6_qp     = limit_uint(rblock->max_raw_ipv6_qp);
 	props->max_raw_ethy_qp     = limit_uint(rblock->max_raw_ethy_qp);
 	props->max_mcast_grp       = limit_uint(rblock->max_mcast_grp);