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Message-ID: <CAPv3WKeLYDR3PuspOGU-oVf8tak5aNRDNP0nEN-jDJmoWa-USg@mail.gmail.com>
Date: Tue, 21 Jun 2022 01:21:42 +0200
From: Marcin Wojtas <mw@...ihalf.com>
To: Andrew Lunn <andrew@...n.ch>
Cc: Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
netdev <netdev@...r.kernel.org>,
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Florian Fainelli <f.fainelli@...il.com>,
Vladimir Oltean <olteanv@...il.com>,
"David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>, pabeni@...hat.com,
Russell King - ARM Linux <linux@...linux.org.uk>,
Heiner Kallweit <hkallweit1@...il.com>,
Grzegorz Bernacki <gjb@...ihalf.com>,
Grzegorz Jaszczyk <jaz@...ihalf.com>,
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upstream@...ihalf.com
Subject: Re: [net-next: PATCH 09/12] Documentation: ACPI: DSD: introduce DSA description
pon., 20 cze 2022 o 20:19 Andrew Lunn <andrew@...n.ch> napisaĆ(a):
>
> On Mon, Jun 20, 2022 at 05:02:22PM +0200, Marcin Wojtas wrote:
> > Describe the Distributed Switch Architecture (DSA) - compliant
> > MDIO devices. In ACPI world they are represented as children
> > of the MDIO busses, which are responsible for their enumeration
> > based on the standard _ADR fields and description in _DSD objects
> > under device properties UUID [1].
>
> I would say this is too limiting. In the DT world, they are not
> limited to MDIO children. They can be I2C children, SPI children
> etc. There are plenty of I2C switches and SPI switches. This is
> actually something we got wrong with the first DT binding. We simply
> translated the platform data in DT, and at that time, there was only
> MDIO switches supported. That was a real blocker to I2C, SPI and MMIO
> devices until we discarded the DT binding and had a second go.
>
> DSA switches are just devices on a bus, any sort of bus.
>
> Look at Documentation/devicetree/binding/net/dsa/dsa.yaml. There is no
> reference to MDIO.
>
> I would expect the same with ACPI. Somehow the bus enumerates and
> instantiates a device on the bus. The device then registers itself
> with the DSA core. The DSA core does not care what sort of bus it is
> on, that is the drivers problem.
>
Thanks for mentioning the other options. It makes things easier and
the MDIO as current strict dependency will be dropped.
Best regards,
Marcin
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