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Date:   Tue, 21 Nov 2023 15:56:50 +0100
From:   =?UTF-8?B?S8O2cnk=?= Maincent <kory.maincent@bootlin.com>
To:     Andrew Lunn <andrew@lunn.ch>
Cc:     Oleksij Rempel <o.rempel@pengutronix.de>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Russ Weight <russ.weight@linux.dev>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-doc@vger.kernel.org, devicetree@vger.kernel.org
Subject: Re: [PATCH net-next 2/9] ethtool: Expand Ethernet Power Equipment
 with PoE alongside PoDL
Message-ID: <20231121155650.5c0d2f82@kmaincent-XPS-13-7390>
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        <20231116-feature_poe-v1-2-be48044bf249@bootlin.com>
        <04cb7d87-bb6b-4997-878d-490c17bfdfd0@lunn.ch>
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        <20231120111008.GC590719@pengutronix.de>
        <2539b109-72ad-470a-9dae-9f53de4f64ec@lunn.ch>
        <20231121110215.07f61e55@kmaincent-XPS-13-7390>
        <44cbe9d3-dbd2-438c-b413-af525426781a@lunn.ch>
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On Tue, 21 Nov 2023 15:19:19 +0100
Andrew Lunn <andrew@lunn.ch> wrote:

> > > However, everything not PoDL PSE seems to be clause 33. So how about:
> > >=20
> > > 	enum ethtool_podl_pse_admin_state podl_admin_control;
> > > 	enum ethtool_c33_pse_admin_state c33_admin_control; =20
> > >=20
> > > At least inside the kernel we use c22, c45, c37 etc. I'm not sure they
> > > are visible to userspace, but if we don't have a better name, maybe we
> > > have to use c33 in userspace as well.
> > >=20
> > > I do think naming like this makes it clear we are talking about two
> > > parallel technologies, not a generic layer and then extensions for
> > > podl.
> > >=20
> > > What do you think? =20
> >=20
> > If we decide to add a prefix, "c33" is precise but less easily
> > understandable, why not using simply "poe" prefix? =20
>=20
> I suspect poe has the exact opposite problem, its too imprecise. Its
> too much of a marketing name, with no clear meaning. It could even be
> some people call podl poe.
>=20
> To some extent, this is a user space UX problem. We can be precises in
> the kernel and the kAPI. What ethtool decides to show to the user
> could be different. Although it basically is the same problem.

Alright, thanks for your answer.

> Do you have ethtool patches? What does the output look like?  Oleksij
> did say a hybrid could be possible, so we probably want ethtool to
> group these properties together and make it clear what is PoDL and
> !PoDL.

No I don't, I am only using ynl for now.
I would be similar to podl:
https://kernel.googlesource.com/pub/scm/network/ethtool/ethtool/+/e6cc6807f=
87c74d4e5b1f1e9d21d3a74e75a258b/netlink/pse-pd.c

Duplicating the PoDL part with c33. Using the same --set-pse and --show-pse
options.

> > Maybe as POE were originally PMDI you prefer to use c33 which won't cha=
nge
> > over time?=20
> >=20
> > Should I also modify the content of the enum?
> > ETHTOOL_PSE_ADMIN_STATE_* to ETHTOOL_C33_PSE_ADMIN_*
> > ETHTOOL_PSE_PW_D_STATUS_* to ETHTOOL_C33_PSE_PW_D_STATUS_* =20
>=20
> Yes. That will help avoid getting PODL and C33 properties missed up.

Alright.

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