Re: gpsd + chrony + pps

[Gary E. Miller]

Yo Dan!

On Thu, 18 Jun 2020 15:18:12 -0400
Dan Williams <dwilliams@nextdroid.com> wrote:

> Because this works:
> > refclock SOCK /var/run/chrony.pps0.sock refid PPS2 lock GNSS
> > refclock PPS /dev/pps0 refid PPS3 lock GNSS  
> 
> But this doesn't:
> > For the socket method, i can't use chrony.tty***.sock it doesn't
> > work  

It will not work with asterisks.

> I think what's happened is that the /var/run/chrony.*.sock will
> correspond to one of two different types of pps source :

Knowing is better than thinking.  Know from the code:

RUNDIR "/chrony.%s.sock", basename(session->gpsdata.dev.path));

Where RUNDIR is usually /run or /var/run.  Chronyd creates the file,
and gpsd opens it.

So PPS, from /dev/pps0 is /run/chrony.pps0.sock

And NMEA, from /dev/ttyS0 is /run/chrony.ttyS0.sock

> Trying to read from the .sock entry corresponding to the inactive PPS
> , well that makes sense that it would break.

Not broken, inactive.

> Personally, I think the documentation (charitably speaking) glosses
> over this as an "obvious" thing to change;  what information would
> make that section clearer / easier to understand?

Doc patches welcome.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        gem@rellim.com  Tel:+1 541 382 8588

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