linuxptp-users

[Linuxptp-users] software timestamp mode

[frank <sou...@gm...>]

Hi,

I would like to use linuxptp in a project using hardware timestamp mode.
The project accesses the ptp time by calling clock_gettime with a
clock_id derived from /dev/ptp0.

However my automatic regression system host(jenkins) does not support
this mode.
So I modified the ptp4l.conf file to use
..
time_stamping software
..

There seems to be ptp activity and the host even seems to become master
for the ptp system,
but I cannot get the ptp time as /dev/ptp0 does not exist.

Do I need to change more configuration settings? Or is this the wrong
way to do things?

kind regards
  Frank

Re: [Linuxptp-users] software timestamp mode

[Richard C. <ric...@gm...>]

On Wed, Nov 04, 2015 at 08:29:06AM +0100, frank wrote:
> Do I need to change more configuration settings? Or is this the wrong
> way to do things?

The choices are:

1. HW time stamping with PHC
2. SW time stamping with the system clock (CLOCK_REALTIME)

You cannot mix the two.  So, for SW time stamping, leave off the '-p'
command line flag.

Thanks,
Richard

Re: [Linuxptp-users] software timestamp mode

[frank <sou...@gm...>]

On 11/04/2015 11:34 AM, Richard Cochran wrote:
> On Wed, Nov 04, 2015 at 08:29:06AM +0100, frank wrote:
>> Do I need to change more configuration settings? Or is this the wrong
>> way to do things?
> The choices are:
>
> 1. HW time stamping with PHC
> 2. SW time stamping with the system clock (CLOCK_REALTIME)
>
> You cannot mix the two.  So, for SW time stamping, leave off the '-p'
> command line flag.
Ah ok, thanks!

Just for my understanding:

ptp4l with software timestamping modifies CLOCK_REALTIME directly,
whereas for hardware timestamping I have to use ptp4l + phc2sys  in order
to achieve the same?

kind regards
  Frank

Re: [Linuxptp-users] software timestamp mode

[Richard C. <ric...@gm...>]

On Thu, Nov 05, 2015 at 11:44:57AM +0100, frank wrote:
> ptp4l with software timestamping modifies CLOCK_REALTIME directly,
> whereas for hardware timestamping I have to use ptp4l + phc2sys  in order
> to achieve the same?

Yes.

Thanks,
Richard