[LinuxPPS] Re: OK, Progress...

[Rodolfo Giometti]

On Tue, Sep 18, 2007 at 12:08:56PM -0600, clemens at dwf.com wrote:
> Thanks for your response to my last note, when I point ppstest (or ntp)
> at /dev/pps1 everything works.

:)

> I will be cleaning up my patch to the refclock_oncore driver in ntpd but
> I still have a couple of questions (sigh).
> 
> (1) looking at your ppstest.c program, you use readlink to get to the 'true'
> name of the device, but since all you do with the returned path is open a file,
> this would work with a symbolic link just as well.

You are right, I'll modify ppstest.c. Thanks.

> I see no path thru this code for your special GPIO pin case.

All PPS sources are mapped into /dev/ppsN devices so even my GPIO pin
source works so.

> (2) Trying ppstest on /dev/pps0 (my parallel port with a cable to the PPS)
> I still see nothing (well, it says 'Connection timed out').
> Looking at /sys/class/pps/pps0/assert I just see 0.000000000#0, 
> in /proc/interrupts I see no count next to parport0 where 
> I assume the counts would accumulate.  So this is still a problem.

Do you see new interrupts for the parallel port into /proc/interrupts?
Please, verify that parport is using the interrupt line of your
parallel port.

   $ cat /proc/interrupts 
              CPU0       CPU1       
     0:   14991694          0  local-APIC-edge  timer
     1:      23509          0    IO-APIC-edge  i8042
     6:          5          0    IO-APIC-edge  floppy
     7:          0          0    IO-APIC-edge  parport0
     8:          2          0    IO-APIC-edge  rtc
    12:       3749          0    IO-APIC-edge  i8042
    15:    1403279          0    IO-APIC-edge  ide1
   ...

On your system you should see that the number under CPUx increments
each second.

> In two weeks I will actually have some free time and can take a look
> at this parallel code.

Great! Thanks.

> Again, if anyone else has this working I would like to hear from
> you.

In the next week I'll be in holland for holidays so most probably I
cannot read my incoming mailbox... :'(

Ciao,

Rodolfo

-- 

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