Re: [chrony-users] Hardware timestamping in CentOS 7.4 (was: Possible to get sub-millisecond accuracy?)

[Miroslav Lichvar <mlichvar@xxxxxxxxxx>]

On Fri, Jun 23, 2017 at 02:38:26PM -0400, Chris Perl wrote:
> On Fri, Jun 23, 2017 at 1:10 PM, Miroslav Lichvar <mlichvar@xxxxxxxxxx> wrote:
> > I think we can support it, at least with a new option that would
> > disable the filter. I actually have a patch in my queue to allow
> > disabling the new NTP-specific filter, which should be added in 4.13
> > (although there is currently no HW that supports both). I can rework
> > the option to select a specific filter and allow "none", which would
> > disable RX timestamping.
> 
> I'm not sure I follow.  What is the new NTP-specific filter?

There is a HW which can be configured to timestamp either NTP packets
or PTP packets, but not all packets. A new filter has to be defined in
the kernel to allow use of such HW with NTP.

> > I don't think there will be any changes in the kernel specific to
> > that. It should work even with the 7.3 kernel. The chrony code just
> > needs to be patched to enable the support for SW timestamping without
> > full HW timestamping support.
> 
> Is that work that is already underway or in the queue?  Or is it
> something that you'd take patches for?

It's the patch included in the package from the copr repo. Does it not
work for you?

-- 
Miroslav Lichvar

-- 
To unsubscribe email chrony-users-request@xxxxxxxxxxxxxxxxxxxx 
with "unsubscribe" in the subject.
For help email chrony-users-request@xxxxxxxxxxxxxxxxxxxx 
with "help" in the subject.
Trouble?  Email listmaster@xxxxxxxxxxxxxxxxxxxx.