Re: [PATCH 2/2] net: mdio: reset PHY before attempting to access registers in fwnode_mdiobus_register_phy

[Russell King (Oracle)]

On Wed, Oct 15, 2025 at 11:07:03AM +0200, Buday Csaba wrote:
> On Mon, Oct 13, 2025 at 04:31:10PM +0200, Maxime Chevallier wrote:
> > Hi,
> > 
> > On 13/10/2025 15:55, Buday Csaba wrote:
> > > When the ID of an ethernet PHY is not provided by the 'compatible'
> > > string in the device tree, its actual ID is read via the MDIO bus.
> > > For some PHYs this could be unsafe, since a hard reset may be
> > > necessary to safely access the MDIO registers.
> > > This patch makes it possible to hard-reset an ethernet PHY before
> > > attempting to read the ID, via a new device tree property, called:
> > > `reset-phy-before-probe`.
> > > 
> > > There were previous attempts to implement such functionality, I
> > > tried to collect a few of these (see links).
> > > 
> > > Link: https://lore.kernel.org/lkml/1499346330-12166-2-git-send-email-richard.leitner@xxxxxxxxxxx/
> > > Link: https://lore.kernel.org/all/20230405-net-next-topic-net-phy-reset-v1-0-7e5329f08002@xxxxxxxxxxxxxx/
> > > Link: https://lore.kernel.org/netdev/20250709133222.48802-4-buday.csaba@xxxxxxxxx/
> > > Signed-off-by: Buday Csaba <buday.csaba@xxxxxxxxx>
> > 
> > This should probably be accompanied by a DT binding update,
> > with some justification that this is indeed HW description
> > and not OS confguration.
> > 
> 
> I have the corresponding patch ready, I just wanted this to be accepted
> first. My description was to be:

Please see Documentation/devicetree/bindings/submitting-patches.rst
point 5.

Basically, don't submit code that introduces a new undocumented DT
property without also including the binding update in the patch set.

Thanks.

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