[LinuxPPS] PPS/ntpd fails on fresh startup

[Rodolfo Giometti]

On Tue, Oct 14, 2008 at 02:00:38PM -0500, William S. Brasher wrote:

> /proc/interrupts shows interrupts are coming in.
> 
> cat < /dev/ttyS0 returns the NMEA sentence at once per second.

Everything happens while the PPS source is enabled? If so you should
see the PPS events (see /sys/class/pps/ppsX/{assert,clear}).

> Hmmmm.  I let ntpd configure the serial port after starting ppsldisc, 
> which seems to squash the pps input.
> 
> Since I can receive the NMEA sentence from the port, and can in fact send 
> serial data to the clock through the port, I assumed the port to be 
> minimally configured.  Which says nothing about what ntpd may do to that 
> port when it starts...
> 
> 
> SO:  If I start ntpd in the startup script before I start ppsldisc,
> everything works.   That is, I inserted the ntpd -gqx into the following 
> script: 
> 
> case "$1" in
>         start)
>                 boot_mesg "Starting ntpd..."
>                 /bin/setserial -v /dev/ttyS0 low_latency
>                 sleep 2
>                 ntpd -gqx 
>                 sleep 2
>                 /usr/bin/ppsldisc /dev/ttyS0 &
>                 sleep 2
>                 loadproc /usr/sbin/ntpd -g
>                 sleep 2
>                 killall ppsldisc
>                 ;;

I'm puzzled! O_o

Luca, can you please test this settings too?

Ciao,

Rodolfo

-- 

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