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Date: Mon, 20 Nov 2023 10:44:39 +0100
From: =?UTF-8?B?S8O2cnk=?= Maincent <kory.maincent@bootlin.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: Florian Fainelli <florian.fainelli@broadcom.com>, Broadcom internal
 kernel review list <bcm-kernel-feedback-list@broadcom.com>, Andrew Lunn
 <andrew@lunn.ch>, Heiner Kallweit <hkallweit1@gmail.com>, Russell King
 <linux@armlinux.org.uk>, "David S. Miller" <davem@davemloft.net>, Eric
 Dumazet <edumazet@google.com>, Paolo Abeni <pabeni@redhat.com>, Richard
 Cochran <richardcochran@gmail.com>, Radu Pirea
 <radu-nicolae.pirea@oss.nxp.com>, Jay Vosburgh <j.vosburgh@gmail.com>, Andy
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 <nicolas.ferre@microchip.com>, Claudiu Beznea <claudiu.beznea@tuxon.dev>,
 Willem de Bruijn <willemdebruijn.kernel@gmail.com>, Jonathan Corbet
 <corbet@lwn.net>, Horatiu Vultur <horatiu.vultur@microchip.com>,
 UNGLinuxDriver@microchip.com, Simon Horman <horms@kernel.org>, Vladimir
 Oltean <vladimir.oltean@nxp.com>, Thomas Petazzoni
 <thomas.petazzoni@bootlin.com>, netdev@vger.kernel.org,
 linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Maxime Chevallier
 <maxime.chevallier@bootlin.com>
Subject: Re: [PATCH net-next v7 15/16] net: ethtool: ts: Let the active time
 stamping layer be selectable
Message-ID: <20231120104439.15bfdd09@kmaincent-XPS-13-7390>
In-Reply-To: <20231118183433.30ca1d1a@kernel.org>
References: <20231114-feature_ptp_netnext-v7-0-472e77951e40@bootlin.com>
	<20231114-feature_ptp_netnext-v7-15-472e77951e40@bootlin.com>
	<20231118183433.30ca1d1a@kernel.org>
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X-GND-Sasl: kory.maincent@bootlin.com

On Sat, 18 Nov 2023 18:34:33 -0800
Jakub Kicinski <kuba@kernel.org> wrote:

> On Tue, 14 Nov 2023 12:28:43 +0100 Kory Maincent wrote:
> > +	if (!tb[ETHTOOL_A_TS_LAYER])
> > +		return 0; =20
>=20
> GENL_REQ_ATTR_CHECK(), not sure why anyone would issue this command
> without any useful attr.
>=20
> > +	/* Disable time stamping in the current layer. */
> > +	if (netif_device_present(dev) &&
> > +	    (dev->ts_layer =3D=3D PHY_TIMESTAMPING ||
> > +	    dev->ts_layer =3D=3D MAC_TIMESTAMPING)) {
> > +		ret =3D dev_set_hwtstamp_phylib(dev, &config, info->extack);
> > +		if (ret < 0)
> > +			return ret; =20
>=20
> So you only support PHYLIB?
>=20
> The semantics need to be better documented :(

Yes as we don't really know how each MAC deal with the timestamping
before ndo_hwstamp_get/set. Using phylib only allows us to be sure these ND=
O are
implemented and the management of timestamping is coherent in the MAC. Also=
 It
will push people to move on to these NDOs.

Ok I will add documentation.

--=20
K=C3=B6ry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com