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Date:   Mon, 26 Oct 2020 08:54:51 -0500
From:   Rob Herring <robh@kernel.org>
To:     Florian Fainelli <f.fainelli@gmail.com>
Cc:     Vladimir Oltean <olteanv@gmail.com>,
        Kurt Kanzenbach <kurt.kanzenbach@linutronix.de>,
        Christian Eggers <ceggers@arri.de>,
        Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Helmut Grohne <helmut.grohne@intenta.de>,
        Paul Barker <pbarker@konsulko.com>,
        Codrin Ciubotariu <codrin.ciubotariu@microchip.com>,
        George McCollister <george.mccollister@gmail.com>,
        Marek Vasut <marex@denx.de>,
        Tristram Ha <Tristram.Ha@microchip.com>,
        "David S . Miller" <davem@davemloft.net>,
        Woojung Huh <woojung.huh@microchip.com>,
        Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>,
        netdev@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH net-next 1/9] dt-bindings: net: dsa: convert ksz
 bindings document to yaml
Message-ID: <20201026135451.GA57974@bogus>
References: <20201019172435.4416-1-ceggers@arri.de>
 <20201019172435.4416-2-ceggers@arri.de>
 <87lfg0rrzi.fsf@kurt>
 <20201022001639.ozbfnyc4j2zlysff@skbuf>
 <3cf2e7f8-7dc8-323f-0cee-5a025f748426@gmail.com>
 <87h7qmil8j.fsf@kurt>
 <20201022123735.3mnlzkfmqqrho6n5@skbuf>
 <63bc70fe-30b3-43f1-a54c-b8c82bbdc048@gmail.com>
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On Thu, Oct 22, 2020 at 12:17:26PM -0700, Florian Fainelli wrote:
> On 10/22/20 5:37 AM, Vladimir Oltean wrote:
> > On Thu, Oct 22, 2020 at 12:54:52PM +0200, Kurt Kanzenbach wrote:
> >> On Wed Oct 21 2020, Florian Fainelli wrote:
> >>> On 10/21/2020 5:16 PM, Vladimir Oltean wrote:
> >>>> On Wed, Oct 21, 2020 at 08:52:01AM +0200, Kurt Kanzenbach wrote:
> >>>>> On Mon Oct 19 2020, Christian Eggers wrote:
> >>>>> The node names should be switch. See dsa.yaml.
> >>>>>
> >>>>>> +            compatible = "microchip,ksz9477";
> >>>>>> +            reg = <0>;
> >>>>>> +            reset-gpios = <&gpio5 0 GPIO_ACTIVE_LOW>;
> >>>>>> +
> >>>>>> +            spi-max-frequency = <44000000>;
> >>>>>> +            spi-cpha;
> >>>>>> +            spi-cpol;
> >>>>>> +
> >>>>>> +            ports {
> >>>>>
> >>>>> ethernet-ports are preferred.
> >>>>
> >>>> This is backwards to me, instead of an 'ethernet-switch' with 'ports',
> >>>> we have a 'switch' with 'ethernet-ports'. Whatever.
> >>>
> >>> The rationale AFAIR was that dual Ethernet port controllers like TI's 
> >>> CPSW needed to describe each port as a pseudo Ethernet MAC and using 
> >>> 'ethernet-ports' as a contained allowed to disambiguate with the 'ports' 
> >>> container used in display subsystem descriptions.
> >>
> >> Yes, that was the outcome of previous discussions.
> > 
> > And why would that disambiguation be necessary in the first place? My
> > understanding is that the whole node path provides the necessary
> > namespacing to avoid the confusion. For example, the 'reg' property
> > means 100 things to 100 buses, and no one has an issue with that. I am
> > not expecting an Ethernet switch to have an HDMI port, I might be wrong
> > though.
> 
> The disambiguation is more of a hint given to DT analysis tools to
> validate a given node with little to no knowledge of the containing
> node. I don't really have a dog in the fight here.

A node name should mean 1 and only 1 type/class of node. 'ports' (and 
'port') is for the graph binding.

Rob