From a27a6acb54756600b0504f25efdadc521b12101d Mon Sep 17 00:00:00 2001
From: Ben Dyer <ben.dyer@taguchimail.com>
Date: Fri, 20 Nov 2015 22:29:40 +1100
Subject: [PATCH] Don't call param_opcode unless there are dirty nodes
 [resolves PX4/Firmware#3160]

---
 src/modules/uavcan/uavcan_servers.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/modules/uavcan/uavcan_servers.cpp b/src/modules/uavcan/uavcan_servers.cpp
index ca5bcede66..961002c2e2 100644
--- a/src/modules/uavcan/uavcan_servers.cpp
+++ b/src/modules/uavcan/uavcan_servers.cpp
@@ -523,8 +523,12 @@ pthread_addr_t UavcanServers::run(pthread_addr_t)
 				switch (command_id) {
 				case 1: {
 						// Param save request
-						_param_save_opcode = uavcan::protocol::param::ExecuteOpcode::Request::OPCODE_SAVE;
-						param_opcode(get_next_dirty_node_id(1));
+						int node_id;
+						node_id = get_next_dirty_node_id(1);
+						if (node_id < 128) {
+							_param_save_opcode = uavcan::protocol::param::ExecuteOpcode::Request::OPCODE_SAVE;
+							param_opcode(node_id);
+						}
 						break;
 					}
 				case 2: {