Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.38 as permitted sender) client-ip=23.128.96.38;
Date:   Thu, 23 Nov 2023 16:00:56 +0100
From:   =?UTF-8?B?S8O2cnk=?= Maincent <kory.maincent@bootlin.com>
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     Vladimir Oltean <vladimir.oltean@nxp.com>,
        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 Gospodarek <andy@greyhouse.net>,
        Nicolas Ferre <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>,
        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: <20231123160056.070f3311@kmaincent-XPS-13-7390>
In-Reply-To: <20231122100142.338a2092@kernel.org>
References: <20231120190023.ymog4yb2hcydhmua@skbuf>
        <20231120115839.74ee5492@kernel.org>
        <20231120211759.j5uvijsrgt2jqtwx@skbuf>
        <20231120133737.70dde657@kernel.org>
        <20231120220549.cvsz2ni3wj7mcukh@skbuf>
        <20231121183114.727fb6d7@kmaincent-XPS-13-7390>
        <20231121094354.635ee8cd@kernel.org>
        <20231122144453.5eb0382f@kmaincent-XPS-13-7390>
        <20231122140850.li2mvf6tpo3f2fhh@skbuf>
        <20231122085000.79f2d14c@kernel.org>
        <20231122165517.5cqqfor3zjqgyoow@skbuf>
        <20231122100142.338a2092@kernel.org>
Organization: bootlin
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Wed, 22 Nov 2023 10:01:42 -0800
Jakub Kicinski <kuba@kernel.org> wrote:

> On Wed, 22 Nov 2023 18:55:17 +0200 Vladimir Oltean wrote:
> > > Well, ethtool has been the catch all for a lot of random things
> > > for the longest time. The question is whether we want to extend
> > > ETHTOOL_GET_TS_INFO or add a third API somewhere else. And if we
> > > do - do we also duplicate the functionality of ETHTOOL_GET_TS_INFO
> > > (i.e. getting capabilities)?
> > >=20
> > > My vote is that keeping it in ethtool is less bad than 3rd API.   =20
> >=20
> > With SIOCSHWTSTAMP also implemented by CAN (and presumably also by
> > wireless in the future), I do wonder whether ethtool is the right place
> > for the netlink conversion. =20
>=20
> ethtool currently provides the only way we have to configure ring
> length, ring count, RSS, UDP tunnels etc.
>=20
> It's a matter of taste, IMO ethtool is a bit of a lost cause already
> and keeping things together (ethtool already has TS_INFO) is cleaner
> than spreading them around.
>=20
> > I wouldn't suggest duplicating ETHTOOL_GET_TS_INFO towards the netdev
> > netlink family. =20
>=20
> FTR so far the netdev family is all about SW configuration. We should
> probably keep it that way, so it doesn't become ginormous. It's easy
> enough to create a new family, if needed.

So, do we have a consensus? Vlad, do you agree on putting all under ethtool?

ETHTOOL_GET_TS_INFO will be in charge of replacing the SIOCGHWSTAMP
implementation. Need to add ETHTOOL_A_TSINFO_PHC_INDEX
ETHTOOL_A_TSINFO_QUALIFIER to the request.

ETHTOOL_GET_TS_INFO will list all the hwtstamp provider (aka "{phc_index,
qualifier}") through the dumpit callback. I will add a filter to be able to
list only the hwtstamp provider of one netdev.

ETHTOOL_SET_TS_INFO will be in charge of replacing the SIOCSHWSTAMP
implementation.

Is that ok for you?

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