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Date: Mon, 16 Oct 2023 10:03:13 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: =?UTF-8?B?S8O2cnk=?= Maincent <kory.maincent@bootlin.com>
Cc: Andrew Lunn <andrew@lunn.ch>, Florian Fainelli
 <florian.fainelli@broadcom.com>, netdev@vger.kernel.org,
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 <jacob.e.keller@intel.com>, Maxime Chevallier
 <maxime.chevallier@bootlin.com>
Subject: Re: [PATCH net-next v5 08/16] net: ethtool: Add a command to expose
 current time stamping layer
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On Mon, 16 Oct 2023 18:23:07 +0200 K=C3=B6ry 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)
> >=20
> > I don't think any "integrated" device would support stamps which
> > differ under category 1. =20
>=20
> It was a case reported by Maxime on v3:
> https://lore.kernel.org/netdev/20230324112541.0b3dd38a@pc-7.home/=20

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