Hi everybody,
One of the things that can be annoying is that NTPD cannot do an initial
synchronization from (most) reference clocks over a difference of more than
4 hours.
The reason is that 'refclock_process()' calls 'clocktime()' which in turn
will only accept time stamps that are in a hard-coded window of +/- 4h
around the sample time (== system time). This makes it impossible for
systems to recover from a loss of power if there is no battery-backup
driven hardware clock.
I appreciate the fact that there are clock signals that do not transmit year
information (IRIG-B, as far as I know...) and that clocks using such
signals require some processing of the kind 'clocktime()' does.
But it's still a nuisance if you have a DCF77 or a GPS clock and the system
does not synchronize after boot just because the CMOS is backed by a
GoldCap capacitor instead of a real battery. (And getting different
hardware is *not* an option for some of us!)
I think that the normal panic threshold ('tinker panic') should be the only
limit for the acceptance of time stamps, and a disabled panic threshold
would permit the system to synchronize even without a backup CMOS clock.
While changing the behavior of NTPD wouldn't be too hard to implement I
would like to know *why* the clock processing is implemented the way it is.
Does anybody know an could enlighten me?
--
juergen 'pearly' perlinger
"It's hard to make new errors!"
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