Re: [PATCH v2] of: property: fw_devlink: Add support for "phy-handle" property

From: Rob Herring
Date: Mon Aug 23 2021 - 18:08:48 EST


On Mon, Aug 23, 2021 at 3:49 PM Saravana Kannan <saravanak@xxxxxxxxxx> wrote:
>
> On Mon, Aug 23, 2021 at 12:58 PM Andrew Lunn <andrew@xxxxxxx> wrote:
> >
> > > PHY seems to be one of those cases where it's okay to have the
> > > compatible property but also okay to not have it.
> >
> > Correct. They are like PCI or USB devices. You can ask it, what are
> > you? There are two registers in standard locations which give you a
> > vendor and product ID. We use that to find the correct driver.
>
> For all the cases of PHYs that currently don't need any compatible
> string, requiring a compatible string of type "ethernet-phy-standard"
> would have been nice. That would have made PHYs consistent with the
> general DT norm of "you need a compatible string to be matched with
> the device". Anyway, it's too late to do that now. So I'll have to
> deal with this some other way (I have a bunch of ideas, so it's not
> the end of the world).

This is not the first time the need for compatible strings for MDIO
devices has come up, but MDIO devices are special (evidently). I
should have taken a harder stance on this which should be simply, if
your device requires having a node in DT, then it requires a
compatible string.

Rob