[Linuxptp-devel] [PATCHv3 4/6] servo: add support for weighted samples.

[Miroslav L. <mli...@re...>]

Add weight parameter to the sample function. Samples with smaller weight
are less reliable, they can be ignored by the servo or the adjustments
of the clock can be smaller.

Signed-off-by: Miroslav Lichvar <mli...@re...>
---
 clock.c         | 6 +++---
 linreg.c        | 1 +
 ntpshm.c        | 1 +
 phc2sys.c       | 2 +-
 pi.c            | 1 +
 servo.c         | 3 ++-
 servo.h         | 3 +++
 servo_private.h | 2 +-
 8 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/clock.c b/clock.c
index 71fda50..3350b3d 100644
--- a/clock.c
+++ b/clock.c
@@ -1351,14 +1351,14 @@ int clock_switch_phc(struct clock *c, int phc_index)
 
 enum servo_state clock_synchronize(struct clock *c, tmv_t ingress, tmv_t origin)
 {
-	double adj;
+	double adj, weight;
 	enum servo_state state = SERVO_UNLOCKED;
 
 	c->ingress_ts = ingress;
 
 	tsproc_down_ts(c->tsproc, origin, ingress);
 
-	if (tsproc_update_offset(c->tsproc, &c->master_offset, NULL))
+	if (tsproc_update_offset(c->tsproc, &c->master_offset, &weight))
 		return state;
 
 	if (clock_utc_correct(c, ingress))
@@ -1370,7 +1370,7 @@ enum servo_state clock_synchronize(struct clock *c, tmv_t ingress, tmv_t origin)
 		return clock_no_adjust(c, ingress, origin);
 
 	adj = servo_sample(c->servo, tmv_to_nanoseconds(c->master_offset),
-			   tmv_to_nanoseconds(ingress), &state);
+			   tmv_to_nanoseconds(ingress), weight, &state);
 	c->servo_state = state;
 
 	if (c->stats.max_count > 1) {
diff --git a/linreg.c b/linreg.c
index fde604d..3f7fe9a 100644
--- a/linreg.c
+++ b/linreg.c
@@ -209,6 +209,7 @@ static int get_best_size(struct linreg_servo *s)
 static double linreg_sample(struct servo *servo,
 			    int64_t offset,
 			    uint64_t local_ts,
+			    double weight,
 			    enum servo_state *state)
 {
 	struct linreg_servo *s = container_of(servo, struct linreg_servo, servo);
diff --git a/ntpshm.c b/ntpshm.c
index 21a11cf..8b18e2d 100644
--- a/ntpshm.c
+++ b/ntpshm.c
@@ -80,6 +80,7 @@ static void ntpshm_destroy(struct servo *servo)
 static double ntpshm_sample(struct servo *servo,
 			    int64_t offset,
 			    uint64_t local_ts,
+			    double weight,
 			    enum servo_state *state)
 {
 	struct ntpshm_servo *s = container_of(servo, struct ntpshm_servo, servo);
diff --git a/phc2sys.c b/phc2sys.c
index 23993ac..9ff5bf9 100644
--- a/phc2sys.c
+++ b/phc2sys.c
@@ -469,7 +469,7 @@ static void update_clock(struct node *node, struct clock *clock,
 	if (clock->sanity_check && clockcheck_sample(clock->sanity_check, ts))
 		servo_reset(clock->servo);
 
-	ppb = servo_sample(clock->servo, offset, ts, &state);
+	ppb = servo_sample(clock->servo, offset, ts, 1.0, &state);
 	clock->servo_state = state;
 
 	switch (state) {
diff --git a/pi.c b/pi.c
index c8b8587..9c7b148 100644
--- a/pi.c
+++ b/pi.c
@@ -64,6 +64,7 @@ static void pi_destroy(struct servo *servo)
 static double pi_sample(struct servo *servo,
 			int64_t offset,
 			uint64_t local_ts,
+			double weight,
 			enum servo_state *state)
 {
 	struct pi_servo *s = container_of(servo, struct pi_servo, servo);
diff --git a/servo.c b/servo.c
index f200f75..2739ebd 100644
--- a/servo.c
+++ b/servo.c
@@ -78,11 +78,12 @@ void servo_destroy(struct servo *servo)
 double servo_sample(struct servo *servo,
 		    int64_t offset,
 		    uint64_t local_ts,
+		    double weight,
 		    enum servo_state *state)
 {
 	double r;
 
-	r = servo->sample(servo, offset, local_ts, state);
+	r = servo->sample(servo, offset, local_ts, weight, state);
 
 	if (*state != SERVO_UNLOCKED)
 		servo->first_update = 0;
diff --git a/servo.h b/servo.h
index e054501..4be8c23 100644
--- a/servo.h
+++ b/servo.h
@@ -104,12 +104,15 @@ void servo_destroy(struct servo *servo);
  * @param servo     Pointer to a servo obtained via @ref servo_create().
  * @param offset    The estimated clock offset in nanoseconds.
  * @param local_ts  The local time stamp of the sample in nanoseconds.
+ * @param weight    The weight of the sample, larger if more reliable,
+ *                  1.0 is the maximum value.
  * @param state     Returns the servo's state.
  * @return The clock adjustment in parts per billion.
  */
 double servo_sample(struct servo *servo,
 		    int64_t offset,
 		    uint64_t local_ts,
+		    double weight,
 		    enum servo_state *state);
 
 /**
diff --git a/servo_private.h b/servo_private.h
index 9a1a459..b8c3c98 100644
--- a/servo_private.h
+++ b/servo_private.h
@@ -30,7 +30,7 @@ struct servo {
 	void (*destroy)(struct servo *servo);
 
 	double (*sample)(struct servo *servo,
-			 int64_t offset, uint64_t local_ts,
+			 int64_t offset, uint64_t local_ts, double weight,
 			 enum servo_state *state);
 
 	void (*sync_interval)(struct servo *servo, double interval);
-- 
2.1.0