[Linuxptp-devel] [PATCH] phc2sys: improve servo start up

[Miroslav Lichvar]

---
phc2sys.c | 15 +++++++--------
1 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/phc2sys.c b/phc2sys.c
index e51c649..32b03b2 100644
--- a/phc2sys.c
+++ b/phc2sys.c
@@ -122,7 +122,8 @@ static int read_phc(clockid_t clkid, clockid_t sysclk, int rdelay, int64_t *offs
}

struct servo {
- uint64_t last_ts;
+ uint64_t saved_ts;
+ int64_t saved_offset;
double drift;
enum {
SAMPLE_0, SAMPLE_1, SAMPLE_2, SAMPLE_3, SAMPLE_N
@@ -136,7 +137,6 @@ static void do_servo(struct servo *srv,
int64_t offset, uint64_t ts, double kp, double ki)
{
double ki_term, ppb;
- int64_t delta;

printf("s%d %lld.%09llu drift %.2f\n",
srv->state, ts / NS_PER_SEC, ts % NS_PER_SEC, srv->drift);
@@ -144,19 +144,20 @@ static void do_servo(struct servo *srv,
switch (srv->state) {
case SAMPLE_0:
clock_ppb(dst, 0.0);
+ srv->saved_offset = offset;
+ srv->saved_ts = ts;
srv->state = SAMPLE_1;
break;
case SAMPLE_1:
srv->state = SAMPLE_2;
break;
case SAMPLE_2:
- delta = ts - srv->last_ts;
- offset = delta - NS_PER_SEC;
- srv->drift = offset;
- clock_ppb(dst, -offset);
srv->state = SAMPLE_3;
break;
case SAMPLE_3:
+ srv->drift = (offset - srv->saved_offset) * 1e9 /
+ (ts - srv->saved_ts);
+ clock_ppb(dst, -srv->drift);
clock_step(dst, -offset);
srv->state = SAMPLE_N;
break;
@@ -173,8 +174,6 @@ static void do_servo(struct servo *srv,
clock_ppb(dst, -ppb);
break;
}
-
- srv->last_ts = ts;
}

static int read_pps(int fd, int64_t *offset, uint64_t *ts)

[Richard Cochran]

Post by Miroslav Lichvar
---
phc2sys.c | 15 +++++++--------
1 files changed, 7 insertions(+), 8 deletions(-)

Applied.

Thanks,
Richard