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Date:   Wed, 7 Dec 2022 17:17:28 +0100
From:   Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
To:     Andrew Lunn <andrew@lunn.ch>
Cc:     Jakub Kicinski <kuba@kernel.org>,
        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>, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, Oleksij Rempel <o.rempel@pengutronix.de>
Subject: Re: [PATCH v5 net-next 1/5] net/ethtool: add netlink interface for
 the PLCA RS
Message-ID: <Y5C8mIQWpWmfmkJ0@gvm01>
References: <cover.1670371013.git.piergiorgio.beruto@gmail.com>
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 <Y5CgIL+cu4Fv43vy@lunn.ch>
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On Wed, Dec 07, 2022 at 05:06:42PM +0100, Andrew Lunn wrote:
> On Wed, Dec 07, 2022 at 04:42:15PM +0100, Piergiorgio Beruto wrote:
> > On Wed, Dec 07, 2022 at 03:16:00PM +0100, Andrew Lunn wrote:
> > > > > TBH I can't parse the "ETHTOOL_A_PLCA_VERSION is reported as 0Axx
> > > > > where.." sentence. Specifically I'm confused about what the 0A is.
> > > > How about this: "When this standard is supported, the upper byte of
> > > > ``ETHTOOL_A_PLCA_VERSION`` shall be 0x0A (see Table A.1.0 — IDVER 
> > > > bits assignment).
> > > 
> > > I think the 0x0A is pointless and should not be included here. If the
> > > register does not contain 0x0A, the device does not follow the open
> > > alliance standard, and hence the lower part of the register is
> > > meaningless.
> > > 
> > > This is why i suggested -ENODEV should actually be returned on invalid
> > > values in this register.
> > I already integrated this change in v5 (returning -ENODEV). Give what you're
> > saying, I can just remove that sentence from the documentations. Agreed?
> 
> And only return the actual version value, not the 0x0A.
About this, at the moment I am reporting the 0x0A to allow in the future
possible extensions of the standard. A single byte for the version may
be too limited given this technology is relatively fresh.
What you think of this?