Subject: Re: [PATCH net-next v5 08/16] net: ethtool: Add a command to expose current time stamping layer

From: Jakub Kicinski <[email-masked]>
Date: Mon, 16 Oct 2023 10:03:13 -0700

On Mon, 16 Oct 2023 18:23:07 +0200 Köry Maincent wrote:
> > What's the reason for timestamp precision differences?
> > My understanding so far was the the differences come from:
> >  1. different stamping device (i.e. separate "piece of silicon",
> >     accessed over a different bus, with different PHC etc.)
> >  2. different stamping point (MAC vs DMA)
> > 
> > I don't think any "integrated" device would support stamps which
> > differ under category 1.  
> 
> It was a case reported by Maxime on v3:
> https://lore.kernel.org/netdev/[email-masked]/ 

IMHO this talks about how clock control/disciplining works which
is a somewhat independent topic of timestamping.