On Thu, Aug 30, 2018 at 12:59:12AM +0200, TheMazzim M wrote:
> 2) The igb driver is loaded for the NIC on this PC104. As a result, the ptp
> module is loaded as well.

You can believe the ethtool output.

> As I understand, this is further evidence that
> hardware time stamping is supported??  Yet, the kernel (question 1) appears
> not to be compliant??  What am I missing?

No, your kernel configuration is okay.
 
> After some time, I see the following "error". What is this trying to tell
> me??
...
> *ptp4l[7816.367]: increasing tx_timestamp_timeout may correct this issue,
> but it is likely caused by a driver bug*

Well, there is a driver bug.  There is a fix upstream, but your old
4.2 kernel lacks the fix.  You can either upgrade your kernel or
back port the fix.

> 4) NOTE: As instructed by the Deployment Guide, since I would ultimately
> like hardware timestamping, I also issue the phc2sys as
> 
> *phc2sys -m -c eth3 -s CLOCK_REALTIME -w*
> 
> Which outputs:
> *phc2sys[20583.688]: p4p1 sys offset       -32 s2 freq  -84541 delay   8096*
> *phc2sys[20584.688]: p4p1 sys offset       -45 s2 freq  -84564 delay   8096*
> *phc2sys[20585.688]: p4p1 sys offset       -32 s2 freq  -84565 delay   8016*

...

> What are the units of sys offset??

nanoseconds.

> Does this seem like a "healthy"
> situation between ptp4l and phc2sys??

Looks okay.
 
> 5) The PTP time code is needed by custom A/D devices that time tag each
> sample with the PTP time.   I've discovered that they do not remove the UTC
> offset (37 seconds) as reported by the PTP sync packets when I use hardware
> timestamping.  This problem disappears if I use software timestamping. The
> manufacturer of the A/D's would look into this "bug".  If I wanted to
> continue to use hardware timestamps, could I force a UTC_OFFSET of 0
> seconds in the ptp4l config file.???

You can set the TAI-UTC offset to zero if that suits your needs.
After all, you have a closed environment.

The A/D slaves might be paying attention to the currentUtcOffsetValid
field in the Announce message from your GM.  By default, when ptp4l is
a GM, that flag will be cleared to false.  You can set it to 'true'
using the GRANDMASTER_SETTINGS_NP management message.

Thanks,
Richard

------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Linuxptp-users mailing list
Linuxptp-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linuxptp-users

Reply via email to