CCS/AM4378: PTP timestamp

Tool/software: Code Composer Studio

Hi:

I am trying to use the timestamp.

Host :Ubuntu 18

1.When I try to read the timestamp by this code in my Host:

if (clock_gettime(CLOCK_REALTIME, &ts)) {
perror("clock_gettime");
} 
else {
printf("clock time: %ld.%09ld or %s",
ts.tv_sec, ts.tv_nsec, ctime(&ts.tv_sec));
}

It shows:

clock time: 1570078608.584780715 or Thu Oct  3 12:56:48 2019

and that is correct.

2.But when I try to use this in my Host:

#define DEVICE "/dev/ptp0"
char *device = DEVICE;
fd = open(device, O_RDWR);
if (fd < 0) {
	fprintf(stderr, "opening %s: %s\n", device, strerror(errno));
	return -1;
}
clkid = get_clockid(fd);
if (clock_gettime(clkid, &ts)) {
perror("clock_gettime");
} 
else {
printf("clock time: %ld.%09ld or %s",
ts.tv_sec, ts.tv_nsec, ctime(&ts.tv_sec));
}

It shows:

clock time: 1570107585.623349515 or Thu Oct 3 20:59:45 2019

SO what make the two results different?

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3.Then,I try to synchronize my board

My board:AM4379

Host(ubuntu):sudo  ./ptp4l -E -2 -H -i enp4s0 -l 7 -m -q -p /dev/ptp0 
Slave(board):sudo ./ptp4l -E -2 -H -i eth0 -s -l 7 -m -q -p /dev/ptp0

It works!my board shows:

In my board,I use this code to read timestamp

#define DEVICE "/dev/ptp0"
char *device = DEVICE;
fd = open(device, O_RDWR);
if (fd < 0) {
	fprintf(stderr, "opening %s: %s\n", device, strerror(errno));
	return -1;
}
clkid = get_clockid(fd);
if (clock_gettime(clkid, &ts)) {
perror("clock_gettime");
} 
else {
printf("clock time: %ld.%09ld or %s",
ts.tv_sec, ts.tv_nsec, ctime(&ts.tv_sec));
}

It shows:

the time is correct but the timestamp is not the same to my host

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I want to get the timestamp in my board.the timestamp should be the same with my host(Ubuntu)

So what is the problem maybe?

Regards.