Re: SOCK on RedHat-8 gpsd-3.19-4.el8.1

[Gary E. Miller]

Yo David!

gpsd-3.19-4.el8.1 is both old, and not from us.  So not supported
for both reasons.

On Mon, 11 Apr 2022 15:29:40 -0700
David Cottle <webmaster@aus-city.com> wrote:

> Has anybody got SOCK running on RedHat-8 / CentOS-8?

If that did not work, we woulda heard the screams instantly.

> I’m using an old Motorola in binary mode with PPS over serial.

I hope the model does not matter.

> Configured /etc/sysconfig/gpsd it’s ttyS0, etc.

That is also not part of gpsd.

> Set options in chrony.conf.
> # SHM0 from gpsd is the NMEA data at 4800bps, so is not very accurate
> refclock SHM 0 refid GPS precision 1e-1 offset 0.9999
> #
> # PPS is from the /dev/pps0 device.  Note that
> # chronyd creates the /var/run/chrony.ttyS1.sock device, but
> # gpsd creates the /dev/pps0 device
> # openrc rules start gpsd /after/ chronyd, so /dev/pps0 
> #   is not created until after chronyd is started
> #   If you want to use pps0, either edit the openrc rules
> #   or add this source after gpsd is started
> #
> refclock PPS /dev/pps0 refid PPS precision 1e-7
> #
> # SOCK protocol also includes PPS data and 
> # it also provides time within a few ns
> refclock SOCK /var/run/chrony.ttyS0.sock delay 0.0 refid SOCK

Normally you either have gpsd read both ttyS0 and /dev/pps0, or neither.

What options is gpsd running with?

You can check this way: 
    # pstree -paul | fgrep gpsd

> Result I’m seeing:

Something wrong with your SOCK.  You need to send the output from 
loge level "-D 4".

> I’ve disabled firewalld and tried selinux permissive. Can’t get the
> SOCK time.

Does  /var/run/chrony.ttyS0.sock exist?  Does it exist before you run gpsd?

Why would you want both SHM and SOCK?  They give the same result.
NTP also supports SHM, but not SOCK.  So SHM is the more common
interface.

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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    "If you can't measure it, you can't improve it." - Lord Kelvin

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