34 lines
1.2 KiB
Diff
34 lines
1.2 KiB
Diff
commit abb09418b16993ecd8289dd459dff91701f4f971
|
|
Author: Miroslav Lichvar <mlichvar@redhat.com>
|
|
Date: Wed Apr 19 12:20:14 2017 +0200
|
|
|
|
sys_linux: don't drop PHC samples with zero delay
|
|
|
|
When processing data from the PTP_SYS_OFFSET ioctl, the sample is
|
|
dropped when an interval between two consecutive readings of the system
|
|
clock is negative or zero, assuming the clock has been stepped between
|
|
the two readings.
|
|
|
|
With a real PHC the interval is normally expected to be at least a
|
|
microsecond, but with a virtual PHC and a low-resolution system clock
|
|
it's possible to get two readings with the same system time. Modify the
|
|
check to drop only samples with a negative delay.
|
|
|
|
diff --git a/sys_linux.c b/sys_linux.c
|
|
index c06112a..649afb0 100644
|
|
--- a/sys_linux.c
|
|
+++ b/sys_linux.c
|
|
@@ -705,9 +705,11 @@ get_phc_sample(int phc_fd, double precision, struct timespec *phc_ts,
|
|
phc_tss[i] = ts2;
|
|
delays[i] = UTI_DiffTimespecsToDouble(&ts3, &ts1);
|
|
|
|
- if (delays[i] <= 0.0)
|
|
+ if (delays[i] < 0.0) {
|
|
/* Step in the middle of a PHC reading? */
|
|
+ DEBUG_LOG(LOGF_SysLinux, "Bad PTP_SYS_OFFSET sample delay=%e", delays[i]);
|
|
return 0;
|
|
+ }
|
|
|
|
if (!i || delays[i] < min_delay)
|
|
min_delay = delays[i];
|