Re: [gpsd-dev] PPS from position hold / time-only modes

[Håkan Johansson]

> > Before going to the solution, I believe the two checks in
> > report_hook() in timehint.c inside the
> >
> > /* FIXME! these two validations need to move back into ppsthread.c */
> >
> > are duplicates of the (longer) check block in gpsd.c,
>
> If they were duplicates then I would not have added the comment.
>
> > (Saving the comment in gpsd.c and also using
> > PPS_MIN_FIXES instead of 0 for the check.)
>
> You can't just use PPS_MIN_FIXES, you need positive indication from the
> GPS that the PPS is good, in this cycle.

I just meant that if the two fixcnt checks are duplicates, then one should 
use the stricter PPS_MIN_FIXES requirement.

I still think the fixcnt check is duplicated:

When

gpsd.c:1520:
    } else if ( 0 >= device->fixcnt ) {

fails, then

gpsd:1543:
                pps_thread_fixin(&ppsonly->pps_thread, &td);

will not be executed, and thus also not

ppsthreads.c:439:
    *last_fixtime = thread_context->fix_in;

making

ppsthreads.c:1021:
        if (last_fixtime.real.tv_sec == 0) {

fail and the fresh PPS sample is rejected, not making it beyond

ppsthreads.c:1036:
            continue;

If it would make it past that point, then it should be shipped to
ntpd/chrondy by:

ppsthreads.c:1105:
                log1 = thread_context->report_hook(thread_context, &ppstimes);

(i.e. report_hook of timehint.c:353:), but that has a check also:

timehint.c:377:
        if (session->fixcnt <= PPS_MIN_FIXES)

Which would be the duplicate check.

Maybe I missed something?

Best regards,
Håkan