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Date:   Fri, 13 Oct 2023 18:11:19 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     =?iso-8859-1?Q?K=F6ry?= Maincent <kory.maincent@bootlin.com>,
        Florian Fainelli <florian.fainelli@broadcom.com>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
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        Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
        "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
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        Jonathan Corbet <corbet@lwn.net>,
        Jay Vosburgh <j.vosburgh@gmail.com>,
        Andy Gospodarek <andy@greyhouse.net>,
        Nicolas Ferre <nicolas.ferre@microchip.com>,
        Claudiu Beznea <claudiu.beznea@tuxon.dev>,
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        UNGLinuxDriver@microchip.com,
        Broadcom internal kernel review list 
        <bcm-kernel-feedback-list@broadcom.com>,
        Heiner Kallweit <hkallweit1@gmail.com>,
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        Richard Cochran <richardcochran@gmail.com>,
        Radu Pirea <radu-nicolae.pirea@oss.nxp.com>,
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        Michael Walle <michael@walle.cc>,
        Jacob Keller <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
Message-ID: <6ef6418d-6e63-49bd-bcc1-cdc6eb0da2d5@lunn.ch>
References: <20231009155138.86458-1-kory.maincent@bootlin.com>
 <20231009155138.86458-9-kory.maincent@bootlin.com>
 <2fbde275-e60b-473d-8488-8f0aa637c294@broadcom.com>
 <20231010102343.3529e4a7@kmaincent-XPS-13-7390>
 <20231013090020.34e9f125@kernel.org>
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> > All these possibles timestamps go through exclusively the netdev API or the
> > phylib API. Even the software timestamping is done in the netdev driver,
> > therefore it goes through the netdev API and then should have the
> > NETDEV_TIMESTAMPING bit set.
> 
> Netdev vs phylib is an implementation detail of Linux.
> I'm also surprised that you changed this.
> 
> > > > + */
> > > > +enum {
> > > > +	NO_TIMESTAMPING = 0,
> > > > +	NETDEV_TIMESTAMPING = (1 << 0),
> > > > +	PHYLIB_TIMESTAMPING = (1 << 1),
> > > > +	SOFTWARE_TIMESTAMPING = (1 << 2) | (1 << 0),    

Just emphasising Jakubs point here. phylib is an implementation
detail, in that the MAC driver might be using firmware to drive its
PHY, and that firmware can do a timestamp in the PHY. The API being
defined here should be independent of the implementation details. So
it probably should be MAC_TIMESTAMPING and PHY_TIMESTAMPING, and leave
it to the driver to decide if its PHYLIB doing the actual work, or
firmware.

	Andrew