Re: PPS stopped once => stopped forever?

[Gary E. Miller]

Yo Ulrich!

On Mon, 4 Nov 2024 12:38:11 +0000
"Wielant, Ulrich" <U.Wielant@leonardogermany.com> wrote:

> > > Ok, understood. Is there any way to change that?  
> >
> > No.  But you can use SHM(2) and SHM(3).  That is not a good idea.  
> 
> Sorry, I don't understand what you recommend.

I recommended nothing.  That is why I said: "not a good idea".

> > > I am using chrony. Does this problem disappear by using sockets
> > > instead of SHM?  
> >
> > Nope.  It is a design decision.
> >  
> 
> This means gpsd will never forward the PPS signal to chrony/ntp if
> the GPS receiver is started after gpsd.

Correct.  Don't do that!

> Do you see any chance to handle such a case

No.  And trying to do so would be a bad idea.  If you are doing
timekeeping you should start gpsd with the time source on the command
line.  And that source had better be very reliable.

> would it be possible to implement a new variant so that gpsd does
> not exit pps_monitor on error so that it can continue providing PPS
> information after reconnect?

As a general solution no.  Hard enough to get PPS right without trying
to handle error conditions that should never happen.

RGDS
GARY
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