timesyncd: clear ADJ_MAXERROR to keep STA_UNSYNC cleared after jump adjust (#4626)

NTP use jump adjust if system has incorrect time read from RTC during boot.
It is desireble to update RTC time as soon as NTP set correct system time.
Sometimes kernel failed to update RTC due to STA_UNSYNC get set before RTC
update finised. In that case RTC time wouldn't be updated within long time.
The commit makes RTC updates stable.

When NTP do jump time adjust using ADJ_SETOFFSET it clears STA_UNSYNC flag.
If don't clear ADJ_MAXERROR, STA_UNSYNC will be set again by kernel within
1 second (by second_overflow() function). STA_UNSYNC flag prevent RTC updates
in kernel. Sometimes the kernel is able to update RTC withing 1 second,
but sometimes it falied.

diff --git a/src/timesync/timesyncd-manager.c b/src/timesync/timesyncd-manager.c
index a455652a27ffc15bfdf4c6961343c4e3bb096686..6a6c1577c64de84287b98f2903babb0e2d3db2d2 100644 (file)
--- a/src/timesync/timesyncd-manager.c
+++ b/src/timesync/timesyncd-manager.c
@@ -330,11 +330,13 @@ static int manager_adjust_clock(Manager *m, double offset, int leap_sec) {
                 tmx.esterror = 0;
                 log_debug("  adjust (slew): %+.3f sec", offset);
         } else {
-                tmx.modes = ADJ_STATUS | ADJ_NANO | ADJ_SETOFFSET;
+                tmx.modes = ADJ_STATUS | ADJ_NANO | ADJ_SETOFFSET | ADJ_MAXERROR | ADJ_ESTERROR;
 
                 /* ADJ_NANO uses nanoseconds in the microseconds field */
                 tmx.time.tv_sec = (long)offset;
                 tmx.time.tv_usec = (offset - tmx.time.tv_sec) * NSEC_PER_SEC;
+                tmx.maxerror = 0;
+                tmx.esterror = 0;
 
                 /* the kernel expects -0.3s as {-1, 7000.000.000} */
                 if (tmx.time.tv_usec < 0) {