From 7c120409dcb6ad0658f06aef660913450e538f6d Mon Sep 17 00:00:00 2001

From: akochetkov <al.kochet@gmail.com>

Date: Fri, 11 Nov 2016 20:50:46 +0300

Subject: [PATCH] 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.

(cherry picked from commit 5f36e3d30375cf04292bbc1bf3f4d7512cf80139)

---

 src/timesync/timesyncd-manager.c | 4 +++-

 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/timesync/timesyncd-manager.c b/src/timesync/timesyncd-manager.c

index d5e16db3a0..419f0fa279 100644

--- 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) {

-- 

2.9.3