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Date: Thu, 25 Jan 2024 11:00:46 +0200
From: Vladimir Oltean <olteanv@gmail.com>
To: =?utf-8?B?QXLEsW7DpyDDnE5BTA==?= <arinc.unal@arinc9.com>,
	Luiz Angelo Daros de Luca <luizluca@gmail.com>
Cc: Andrew Lunn <andrew@lunn.ch>, Florian Fainelli <f.fainelli@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	mithat.guner@xeront.com, erkin.bozoglu@xeront.com,
	Alvin =?utf-8?Q?=C5=A0ipraga?= <ALSI@bang-olufsen.dk>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next] net: dsa: remove OF-based MDIO bus registration
 from DSA core
Message-ID: <20240125090046.jyggdontwkhthqjh@skbuf>
References: <20240122053348.6589-1-arinc.unal@arinc9.com>
 <20240122053348.6589-1-arinc.unal@arinc9.com>
 <20240123154431.gwhufnatxjppnm64@skbuf>
 <d32d17ed-87b5-4032-b310-f387cea72837@arinc9.com>
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In-Reply-To: <d32d17ed-87b5-4032-b310-f387cea72837@arinc9.com>

On Wed, Jan 24, 2024 at 08:30:11AM +0300, Arınç ÜNAL wrote:
> On 23.01.2024 18:44, Vladimir Oltean wrote:
> > On Mon, Jan 22, 2024 at 08:33:48AM +0300, Arınç ÜNAL wrote:
> > > These subdrivers which control switches [with MDIO bus] probed on OF, will
> > > lose the ability to register the MDIO bus OF-based:
> > > 
> > > drivers/net/dsa/b53/b53_common.c
> > > drivers/net/dsa/lan9303-core.c
> > > drivers/net/dsa/realtek/realtek-mdio.c
> > > drivers/net/dsa/vitesse-vsc73xx-core.c
> > > 
> > > These subdrivers let the DSA core driver register the bus:
> > > - ds->ops->phy_read() and ds->ops->phy_write() are present.
> > > - ds->user_mii_bus is not populated.
> > > 
> > > The commit fe7324b93222 ("net: dsa: OF-ware slave_mii_bus") which brought
> > > OF-based MDIO bus registration on the DSA core driver is reasonably recent
> > > and, in this time frame, there have been no device trees in the Linux
> > > repository that started describing the MDIO bus, or dt-bindings defining
> > > the MDIO bus for the switches these subdrivers control. So I don't expect
> > > any devices to be affected.
> > 
> > IIUC, Luiz made the original patch for the realtek switches. Shouldn't
> > we wait until realtek registers ds->user_mii_bus on its own, before
> > reverting? Otherwise, you're basically saying that Luiz made the DSA
> > core patch without needing it.
> 
> My findings point to that. Luiz made the patch to optionally register the
> MDIO bus of the MDIO controlled Realtek switches OF-based. So it's not
> necessary to wait.
> 
> Arınç

Well, Luiz is copied, he can ack or nack if so.