Re: [Ptpd-devel] No sync, ptpd over WiFi

[Drasko D. <dra...@gm...>]

Hi Jan,

On Mon, Jun 3, 2013 at 11:30 PM, Jan Breuer <jan...@ja...> wrote:
> 2013/6/3 Drasko DRASKOVIC <dra...@gm...>
>
> this is strange. Are you using unmodified version of PTPd?

Unmodified version from SourceForge.

>
> It looks like some other program regulates clock speed e.g. some ntp
> client, NetworkManager or so. Check running processes.

No, no other process of this type. No NetworkManager, and I stopped
all NTP processes.

>
> It is also possible, that frequency adjustment does not work as
> expected. It seems that it adjust 50 times faster;

Can you please tell me how did you concluded this from the logs, as
they do not tell me much.

> 100 ppm adjustment
> means 5000 ppm in reality.

Why is this? I do not see what do you really mean here.

>You can try my drift test program.
> https://github.com/j123b567/adjtimex-test/
> and compare my results from PC to your results on Pandaboard.

Here are my results :
root@speaker:~/adjtimex-test/drift# ./drift 500
usage:
        drift [adjustment - ppm] [measurement time - seconds]

Measuring 10 s with adjustment 0 ppm
Measuring 10 s with adjustment 500 ppm
adjustment =    0 ppm -> measured drift =    3.090 ppm
adjustment =  500 ppm -> measured drift =  499.824 ppm
root@speaker:~/adjtimex-test/drift# ./drift 100
usage:
        drift [adjustment - ppm] [measurement time - seconds]

Measuring 10 s with adjustment 0 ppm
Measuring 10 s with adjustment 100 ppm
adjustment =    0 ppm -> measured drift =   -3.046 ppm
adjustment =  100 ppm -> measured drift =   99.964 ppm

I am wondering is this 0 ppm -> measured drift =    3.090 ppm
dangerous? It comes from the PPS program that I use to toggle GPIO (in
order to observe offest between two boards on scope), and this program
blocks irqs for sam small ammount of time...

BR,
Drasko