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sys_linux: add support for PTP_SYS_OFFSET_EXTENDED ioctl

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A new ioctl will probably be added in Linux 4.21. It should enable a
significantly more accurate measurement of the offset between PHC and
system clock.
This commit is contained in:
Miroslav Lichvar 2018-11-27 13:46:37 +01:00
parent 6b44055e3d
commit cc8414b1b3
1 changed files with 43 additions and 0 deletions
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43
sys_linux.c
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@ -544,6 +544,9 @@ SYS_Linux_EnableSystemCallFilter(int level)
#ifdef PTP_PIN_SETFUNC
PTP_PIN_SETFUNC,
#endif
#ifdef PTP_SYS_OFFSET_EXTENDED
PTP_SYS_OFFSET_EXTENDED,
#endif
#ifdef PTP_SYS_OFFSET_PRECISE
PTP_SYS_OFFSET_PRECISE,
#endif
@ -778,6 +781,42 @@ get_phc_sample(int phc_fd, double precision, struct timespec *phc_ts,
/* ================================================== */
static int
get_extended_phc_sample(int phc_fd, double precision, struct timespec *phc_ts,
struct timespec *sys_ts, double *err)
{
#ifdef PTP_SYS_OFFSET_EXTENDED
struct timespec ts[PHC_READINGS][3];
struct ptp_sys_offset_extended sys_off;
int i;
/* Silence valgrind */
memset(&sys_off, 0, sizeof (sys_off));
sys_off.n_samples = PHC_READINGS;
if (ioctl(phc_fd, PTP_SYS_OFFSET_EXTENDED, &sys_off)) {
DEBUG_LOG("ioctl(%s) failed : %s", "PTP_SYS_OFFSET_EXTENDED", strerror(errno));
return 0;
}
for (i = 0; i < PHC_READINGS; i++) {
ts[i][0].tv_sec = sys_off.ts[i][0].sec;
ts[i][0].tv_nsec = sys_off.ts[i][0].nsec;
ts[i][1].tv_sec = sys_off.ts[i][1].sec;
ts[i][1].tv_nsec = sys_off.ts[i][1].nsec;
ts[i][2].tv_sec = sys_off.ts[i][2].sec;
ts[i][2].tv_nsec = sys_off.ts[i][2].nsec;
}
return process_phc_readings(ts, PHC_READINGS, precision, phc_ts, sys_ts, err);
#else
return 0;
#endif
}
/* ================================================== */
static int
get_precise_phc_sample(int phc_fd, double precision, struct timespec *phc_ts,
struct timespec *sys_ts, double *err)
@ -849,6 +888,10 @@ SYS_Linux_GetPHCSample(int fd, int nocrossts, double precision, int *reading_mod
get_precise_phc_sample(fd, precision, phc_ts, sys_ts, err)) {
*reading_mode = 2;
return 1;
} else if ((*reading_mode == 3 || !*reading_mode) &&
get_extended_phc_sample(fd, precision, phc_ts, sys_ts, err)) {
*reading_mode = 3;
return 1;
} else if ((*reading_mode == 1 || !*reading_mode) &&
get_phc_sample(fd, precision, phc_ts, sys_ts, err)) {
*reading_mode = 1;