> -----Original Message-----
> From: Gary E. Miller [mailto:g...@rellim.com]
> Sent: Tuesday, February 24, 2015 3:06 PM
> To: Keller, Jacob E
> Cc: Jiri Benc; linuxptp-devel@lists.sourceforge.net
> Subject: Re: [Linuxptp-devel] ntp SHMs
> 
> Yo Jacob E!
> 
> On Tue, 24 Feb 2015 22:35:09 +0000
> "Keller, Jacob E" <jacob.e.kel...@intel.com> wrote:
> 
> > Hopefully you can provide the ptp4l results alone without phc2sys or
> > the chronyd interfering.
> 
> Sent, I think.
> 
> > Like I mentioned use the testptp program
> > from the kernel Documentation to sanity check the device's clock.
> 
> If I can figure out how to make it.
> 
> > > kong ~ # ptp4l -i eth0 -l 7 -m -f ptp.conf &
> >
> > I recommend that you run with -l 6 ,since l7 prints a ton of debug
> > information that is nearly always not helpful and clutters reading
> > the time log output.
> 
> Changed.
> 
> > > delay         54241      48536 phc2sys[48410.054]: phc offset
> > > -13318750 s0 freq      +0 delay   1582 ptp4l[48410.078]:
> > > clockcheck: clock jumped forward or running faster than expected!
> >
> > And at this point, the clock jumped. *something* twiddled with the
> > clock.
> 

Ptp4l only cares about the hardware MAC clock :)

> Which clock?  The system clock was stable at that time.
> 

The  MAC clock that ptp4l was synchronizing jumped.

> > The "what" I am not sure. Also it seems weird that the phc
> > switched from a positive to a negative offset..?
> 
> Yup, weird.
> 
> > I assume you put the
> > NTP SHM into chronyd as a refclock?
> 
> Yup.  That way I can compare it to other clocks.  I have a 'watch chronyc
> sources" going, I can see the phc2sys clock goes nuts then it takes a while
> before chronyd takes notice.  Usually chronyd marks it a falsechimer,
> but occasionally follows it to crazy town for a while.
> 
> > > ptp4l[48410.078]: master offset 70368744180811 s0 freq  -10357 path
> > > delay     54241
> > > ptp4l[48410.078]: port 1: SLAVE to UNCALIBRATED on
> > > SYNCHRONIZATION_FAULT
> >
> > At this point ptp4l has reset and now things get funky. I suspect
> > this is either a driver bug, or somehow you have other things
> > controlling the clock. Obviously both of us are stumped on what else
> > could be doing it...
> 

Again, most of the time I assumed it would be clear which clock I was 
referencing due to what portion of the process I was talking about. In this 
case, the MAC clock has gone to crazy town.

> By 'the clock' you mean which clock?  The system clock is not moving.
> So you mean the phc clock?
> 
> > > Clearly bonkers now, so ^C.
> >
> > Yes its bonkers now because of whatever that clock jump invalid event
> > was that very much screwed all the settings.
> 
> Well, at least tow of us see it.
> 
> > > OK, I think that is what I'm doing.  You can see above what I am
> > > doing.
> > Just to clarify, without phc2sys then you only synchronize the MAC
> > hardware clock and not the real system clock.
> 
> Right, and confusing.  In timestamp software mode ptp4l steers the NTP
> SHM (and then possibly, by way of chronyd, the system clock), but in
> timestamp hardware mode phc2sys steers the NTP SHM.
> 
> RGDS
> GARY
> ---------------------------------------------------------------------------
> Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97701
>       g...@rellim.com  Tel:+1(541)382-8588

------------------------------------------------------------------------------
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the 
conversation now. http://goparallel.sourceforge.net/
_______________________________________________
Linuxptp-devel mailing list
Linuxptp-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linuxptp-devel

Reply via email to