[ntp:questions] nmea and initial large offset

Andy Helten andy.helten at dot21rts.com
Fri May 7 17:19:17 UTC 2010

Rob wrote:
> Kalle Pokki <kalle.pokki at iki.fi> wrote:
>> Yes, but reference clock drivers don't use the ntp timestamp. Take a
>> look at e.g. the SHM driver. There
> Is this piece of code something that our friend does not want to change
> because he believes it is doing the right thing?  Or is it merely badly
> written by a contributor and nobody got around to cleaning it up?
> I would say it is completely pointless to decompose a timeval timestamp
> into separate fields and then back.  That only costs CPU time and induces
> errors.

You should read the discussion in the bug report that was previously 
provided by Kalle:  https://bugs.ntp.org/417

It includes justification from David Mills on why it works this way.  I 
don't know that his justification specifically addressed the inability 
to even force a quick sync with a refclock when it differs by more than 
4 hours from system time (i.e. the CLOSETIME stuff).  To me, there is no 
justification for such behavior with respect to forcing a quick sync.  
In such cases, ntpd is saying to the user "I know best" but it turns 
that it doesn't.

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