Re: [PATCH net-next] dt-bindings: net: snps,dwmac: Do not make 'phy-mode' required

[Andrew Lunn <andrew@lunn.ch>]

On Mon, Nov 13, 2023 at 02:03:00PM -0800, Florian Fainelli wrote:
> On 11/13/23 13:51, Andrew Lunn wrote:
> > On Mon, Nov 13, 2023 at 05:40:52PM -0300, Fabio Estevam wrote:
> > > From: Fabio Estevam <festevam@denx.de>
> > > 
> > > The property 'phy-connection-type' can also be used to describe
> > > the interface type between the Ethernet device and the Ethernet PHY
> > > device.
> > > 
> > > Mark 'phy-mode' as a non required property.
> > 
> > Hi Fabio
> > 
> > What does the driver actually require? Will it error out if neither is
> > provided?
> > 
> > Maybe we should be changing the condition that one or the other is
> > required?

Hi Florian

 
> 'phy-connection-type' is the deprecated version of 'phy-mode'

I thought that too, but
Documentation/devicetree/bindings/net/ethernet-controller.yaml does
not mark it deprecated.

The original .txt file has a different wording:

- phy-mode: string, operation mode of the PHY interface. This is now a de-facto
  standard property; supported values are:
  * "internal" (Internal means there is not a standard bus between the MAC and
     the PHY, something proprietary is being used to embed the PHY in the MAC.)
  * "mii"
  * "gmii"

- phy-connection-type: the same as "phy-mode" property but described in the
  Devicetree Specification;

So it could technically be we cannot deprecate phy-connection-type
because it is part of the standard, and we need to accept it.

> which
> of_get_phy_mode() will fall back to if 'phy-mode' is not provided. It does
> not appear that stmmac attempts to use anything other than of_get_phy_mode()
> therefore would not it be acceptable to update the relevant .dts file such
> that it uses 'phy-mode'?

Using phy-mode would be more consistent, since its used > 10x more
than phy-connection-type.

     Andrew