Date:   Sat, 4 Mar 2023 20:46:05 +0100
From:   Andrew Lunn <andrew@lunn.ch>
To:     "Russell King (Oracle)" <linux@armlinux.org.uk>
Cc:     =?iso-8859-1?Q?K=F6ry?= Maincent <kory.maincent@bootlin.com>,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        linux-omap@vger.kernel.org, Michael Walle <michael@walle.cc>,
        Richard Cochran <richardcochran@gmail.com>,
        thomas.petazzoni@bootlin.com, Jay Vosburgh <j.vosburgh@gmail.com>,
        Veaceslav Falico <vfalico@gmail.com>,
        Andy Gospodarek <andy@greyhouse.net>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Joakim Zhang <qiangqing.zhang@nxp.com>,
        Vladimir Oltean <vladimir.oltean@nxp.com>,
        Claudiu Manoil <claudiu.manoil@nxp.com>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        UNGLinuxDriver@microchip.com,
        Grygorii Strashko <grygorii.strashko@ti.com>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Minghao Chi <chi.minghao@zte.com.cn>,
        Jie Wang <wangjie125@huawei.com>,
        Guangbin Huang <huangguangbin2@huawei.com>,
        Wolfram Sang <wsa+renesas@sang-engineering.com>,
        Wang Yufen <wangyufen@huawei.com>,
        Alexandru Tachici <alexandru.tachici@analog.com>,
        Oleksij Rempel <linux@rempel-privat.de>
Subject: Re: [PATCH v2 3/4] net: Let the active time stamping layer be
 selectable.
Message-ID: <94544cd0-18da-40d1-8691-66e50d42bfb4@lunn.ch>
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> The timestamping part is via the netdev, which is a separate entity,
> and its that entity which is responsible for identifying which PHC it
> is connected to (normally by filling in the phc_index field of
> ethtool_ts_info.)
> 
> Think of is as:
> 
>   netdev ---- timestamping ---- PHC
> 
> since we can have:
> 
>   netdev1 ---- timestamping \
>   netdev2 ---- timestamping -*--- PHC
>   netdev3 ---- timestamping /
> 
> Since the ioctl is to do with requesting what we want the timestamping
> layer to be doing with packets, putting it in ptp_clock_info makes
> very little sense.

So there does not appear to be an object to represent a time stamper?

Should one be added? It looks like it needs two ops hwtstamp_set() and
hwtstamp_get(). It would then be registered with the ptp core. And
then the rest of what i said would apply...

	Andrew