Rename _param_sub to _param_update_sub and initialize. Re-define and re-implement the update_params() method and only call if parameters have been updated.

src/modules/mavlink/mavlink_receiver.cpp

@@ -566,10 +566,7 @@ MavlinkReceiver::handle_message_optical_flow_rad(mavlink_message_t *msg)
 	mavlink_optical_flow_rad_t flow;
 	mavlink_msg_optical_flow_rad_decode(msg, &flow);
 
-	/* read flow sensor parameters */
-	const enum Rotation flow_rot = (Rotation)_param_sens_flow_rot.get();
-
-	struct optical_flow_s f = {};
+	optical_flow_s f = {};
 
 	f.timestamp = _mavlink_timesync.sync_stamp(flow.time_usec);
 	f.time_since_last_sonar_update = flow.time_delta_distance_us;
@@ -587,9 +584,12 @@ MavlinkReceiver::handle_message_optical_flow_rad(mavlink_message_t *msg)
 	f.min_ground_distance   = _param_sens_flow_minhgt.get();
 	f.max_ground_distance   = _param_sens_flow_maxhgt.get();
 
+	/* read flow sensor parameters */
+	const Rotation flow_rot = (Rotation)_param_sens_flow_rot.get();
+
 	/* rotate measurements according to parameter */
-	float zeroval = 0.0f;
-	rotate_3f(flow_rot, f.pixel_flow_x_integral, f.pixel_flow_y_integral, zeroval);
+	float zero_val = 0.0f;
+	rotate_3f(flow_rot, f.pixel_flow_x_integral, f.pixel_flow_y_integral, zero_val);
 	rotate_3f(flow_rot, f.gyro_x_rate_integral, f.gyro_y_rate_integral, f.gyro_z_rate_integral);
 
 	if (_flow_pub == nullptr) {
@@ -600,7 +600,7 @@ MavlinkReceiver::handle_message_optical_flow_rad(mavlink_message_t *msg)
 	}
 
 	/* Use distance value for distance sensor topic */
-	struct distance_sensor_s d = {};
+	distance_sensor_s d = {};
 
 	if (flow.distance > 0.0f) { // negative values signal invalid data
 		d.timestamp = f.timestamp;
@@ -2590,7 +2590,10 @@ MavlinkReceiver::receive_thread(void *arg)
 	hrt_abstime last_send_update = 0;
 
 	while (!_mavlink->_task_should_exit) {
-		update_params(false);
+		// Check for updated parameters.
+		if (_param_update_sub.updated()) {
+			update_params();
+		}
 
 		if (poll(&fds[0], 1, timeout) > 0) {
 			if (_mavlink->get_protocol() == SERIAL) {
@@ -2743,15 +2746,9 @@ MavlinkReceiver::receive_start(pthread_t *thread, Mavlink *parent)
 }
 
 void
-MavlinkReceiver::update_params(const bool force)
+MavlinkReceiver::update_params()
 {
-	bool updated;
 	parameter_update_s param_update;
-
-	orb_check(_param_sub, &updated);
-
-	if (updated || force) {
-		updateParams();
-		orb_copy(ORB_ID(parameter_update), _param_sub, &param_update);
-	}
+	_param_update_sub.update(&param_update);
+	updateParams();
 }

src/modules/mavlink/mavlink_receiver.h

@@ -188,10 +188,9 @@ private:
 	void send_storage_information(int storage_id);
 
 	/**
-	 * @brief Updates and checks for updated uORB parameters.
-	 * @param force Boolean to determine if an update check should be forced.
+	 * @brief Checks for updated uORB parameters and updates the params if required.
 	 */
-	void update_params(const bool force = false);
+	void update_params();
 
 	Mavlink	*_mavlink;
 
@@ -261,7 +260,6 @@ private:
 	static constexpr unsigned int MOM_SWITCH_COUNT{8};
 
 	int _orb_class_instance{-1};
-	int _param_sub{-1};
 
 	uint8_t _mom_switch_pos[MOM_SWITCH_COUNT] {};
 
@@ -273,6 +271,8 @@ private:
 
 	bool _hil_local_proj_inited{false};
 
+	uORB::Subscription _param_update_sub{ORB_ID(parameter_update)};
+
 	DEFINE_PARAMETERS(
 		(ParamFloat<px4::params::BAT_CRIT_THR>)     _param_bat_crit_thr,
 		(ParamFloat<px4::params::BAT_EMERGEN_THR>)  _param_bat_emergen_thr,