Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 8 Dec 2022 18:03:36 +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: <Y5IY6FLtndqXqzMn@gvm01>
References: <350e640b5c3c7b9c25f6fd749dc0237e79e1c573.1670371013.git.piergiorgio.beruto@gmail.com>
 <20221206195014.10d7ec82@kernel.org>
 <Y5CQY0pI+4DobFSD@gvm01>
 <Y5CgIL+cu4Fv43vy@lunn.ch>
 <Y5C0V52DjS+1GNhJ@gvm01>
 <Y5C6EomkdTuyjJex@lunn.ch>
 <Y5C8mIQWpWmfmkJ0@gvm01>
 <Y5DR01UWeWRDaLdS@lunn.ch>
 <Y5DfDYr2egl/dZoy@gvm01>
 <Y5DokI3lm8U2eW+G@lunn.ch>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <Y5DokI3lm8U2eW+G@lunn.ch>
Precedence: bulk

On Wed, Dec 07, 2022 at 08:25:04PM +0100, Andrew Lunn wrote:
> > 4.1.1 IDM
> > Constant field indicating that the address space is defined by this document.
> > These bits shall read as 0x0A (Open Alliance).
> 
> So it is local to this document. It has no global meaning within Open
> Alliance, so some other working group could use the same value in the
> same location, and it has a totally different meaning.
Actually, we are sharing an excel file with all register addresses. This file
is internal to the OPEN Alliance, but global across the various TCs. I
understand it is not a strong guarantee, but the OPEN review process should
check that no one else re-uses the same addresses for other purposes.

> 
> Also, 'by this document' means any future changes need to be in this
> document. Except when they are in another document, and decide to
> reuse the value 0x0a because it is local to the document....
No, that cannto happen (see above). Not within the OPEN at least.
Unfortunately, this global excel sheet for registers was introdiced
AFTER the release date of this document, therefore you see this
statement.

> So it actually looks like 0x0a does not have much meaning. 
> 
> So why return it?
> 
> Does Open Alliance have any sort of global registry of magic numbers
> which are unique across specifications? Maybe you want to add another
> register whos value is not defined by this document, but something
> with bigger scope?
AT the moment, only TC14 (T1S) is using the excel sheet I mentioned, but
we're pushing to make this a global registry across all groups.

Given what I just said, what would you suggest to do?

Thanks,
Piergiorgio