Re: [PATCH v1 2/2] of: property: fw_devlink: Add support for "phy-handle" property

From: Saravana Kannan
Date: Tue Aug 17 2021 - 14:19:19 EST


On Mon, Aug 16, 2021 at 2:11 PM Rob Herring <robh+dt@xxxxxxxxxx> wrote:
>
> On Mon, Aug 16, 2021 at 3:43 PM Saravana Kannan <saravanak@xxxxxxxxxx> wrote:
> >
> > On Sat, Aug 14, 2021 at 8:22 AM Andrew Lunn <andrew@xxxxxxx> wrote:
> > >
> > > Hi Saravana
> > >
> > > > Hi Andrew,
> > > >
> > >
> > > > Also there
> > > > are so many phy related properties that my head is spinning. Is there a
> > > > "phy" property (which is different from "phys") that treated exactly as
> > > > "phy-handle"?
> > >
> > > Sorry, i don't understand your question.
> >
> > Sorry. I was just saying I understand the "phy-handle" DT property
> > (seems specific to ethernet PHY) and "phys" DT property (seems to be
> > for generic PHYs -- used mostly by display and USB?). But I noticed
> > there's yet another "phy" DT property which I'm not sure I understand.
> > It seems to be used by display and ethernet and seems to be a
> > deprecated property. If you can explain that DT property in the
> > context of networking and how to interpret it as a human, that'd be
> > nice.
>
> For net devices, you can have 2 PHYs. 'phys' is the serdes phy and
> 'phy-handle' is the ethernet (typically) phy. On some chips, a serdes
> phy can do PCS (ethernet), SATA, PCIe.
>
> 'phy' is deprecated, so ignore it. The one case for displays I see in
> display/exynos/exynos_hdmi.txt should be deprecated as well.
>
> There's also 'usb-phy' which should be deprecated.

Thanks for the explanation Rob. I'll ignore phy and usb-phy unless it
becomes an issue for any future changes/improvements.

-Saravana


-Saravana