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Date: Fri, 5 Jan 2024 07:34:32 -0800
From: Jakub Kicinski <kuba@kernel.org>
To: Maxime Chevallier <maxime.chevallier@bootlin.com>
Cc: davem@davemloft.net, netdev@vger.kernel.org,
 linux-kernel@vger.kernel.org, thomas.petazzoni@bootlin.com, Andrew Lunn
 <andrew@lunn.ch>, Eric Dumazet <edumazet@google.com>, Paolo Abeni
 <pabeni@redhat.com>, Russell King <linux@armlinux.org.uk>,
 linux-arm-kernel@lists.infradead.org, Christophe Leroy
 <christophe.leroy@csgroup.eu>, Herve Codina <herve.codina@bootlin.com>,
 Florian Fainelli <f.fainelli@gmail.com>, Heiner Kallweit
 <hkallweit1@gmail.com>, Vladimir Oltean <vladimir.oltean@nxp.com>,
 =?UTF-8?B?S8O2cnk=?= Maincent <kory.maincent@bootlin.com>, Jesse Brandeburg
 <jesse.brandeburg@intel.com>, Jonathan Corbet <corbet@lwn.net>, Marek
 =?UTF-8?B?QmVow7pu?= <kabel@kernel.org>, Piergiorgio Beruto
 <piergiorgio.beruto@gmail.com>, Oleksij Rempel <o.rempel@pengutronix.de>,
 =?UTF-8?B?Tmljb2zDsg==?= Veronese <nicveronese@gmail.com>, Simon Horman
 <horms@kernel.org>
Subject: Re: [PATCH net-next v5 01/13] net: phy: Introduce ethernet link
 topology representation
Message-ID: <20240105073432.671159e9@kernel.org>
In-Reply-To: <20240105102918.24398552@device-28.home>
References: <20231221180047.1924733-1-maxime.chevallier@bootlin.com>
	<20231221180047.1924733-2-maxime.chevallier@bootlin.com>
	<20240104151242.52fa8cb4@kernel.org>
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On Fri, 5 Jan 2024 10:29:18 +0100 Maxime Chevallier wrote:
> I'll give it a try, it could be doable to try to keep the index for
> _some_ PHYs. I had a first try at this in the very first iteration, but
> that was lost when converting to xarray for the index management. Since
> the phy_device keeps track of its own index, we can try to re-use it,
> but I can see it becoming difficult if we destroy the topology when all
> PHYs are detached (after ndo_close).

What I was thinking is if phy already has phyindex, and that index is
unused in the xarray of netdev in question - try to use that phyindex
instead of allocating a new one?
IDK if phys can move between netdevs, or get freed/recreated
automatically - otherwise it should work? (If user unbinds and rebinds
the PHY driver for instance that's their fault, we can renumber).