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From:   Rob Herring <robh+dt@kernel.org>
Date:   Mon, 16 Aug 2021 16:11:05 -0500
Message-ID: <CAL_JsqJa_8sxdKit_UKHwkuOhK9L=SDYuRAD0vsY7pRE6sM3Qg@mail.gmail.com>
Subject: Re: [PATCH v1 2/2] of: property: fw_devlink: Add support for
 "phy-handle" property
To:     Saravana Kannan <saravanak@google.com>
Cc:     Andrew Lunn <andrew@lunn.ch>,
        Frank Rowand <frowand.list@gmail.com>,
        Android Kernel Team <kernel-team@android.com>,
        devicetree@vger.kernel.org,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        netdev <netdev@vger.kernel.org>
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On Mon, Aug 16, 2021 at 3:43 PM Saravana Kannan <saravanak@google.com> wrote:
>
> On Sat, Aug 14, 2021 at 8:22 AM Andrew Lunn <andrew@lunn.ch> 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.

Rob