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Date:   Fri, 16 Apr 2021 00:27:46 +0200
From:   Michael Walle <michael@walle.cc>
To:     Rob Herring <robh@kernel.org>
Cc:     Andrew Lunn <andrew@lunn.ch>, netdev@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>,
        Frank Rowand <frowand.list@gmail.com>
Subject: Re: [PATCH net-next 1/3] dt-bindings: net: add
 nvmem-mac-address-offset property
In-Reply-To: <20210415215955.GA1937954@robh.at.kernel.org>
References: <20210414152657.12097-1-michael@walle.cc>
 <20210414152657.12097-2-michael@walle.cc> <YHcNtdq+oIYcB08+@lunn.ch>
 <20210415215955.GA1937954@robh.at.kernel.org>
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Am 2021-04-15 23:59, schrieb Rob Herring:
> On Wed, Apr 14, 2021 at 05:43:49PM +0200, Andrew Lunn wrote:
>> On Wed, Apr 14, 2021 at 05:26:55PM +0200, Michael Walle wrote:
>> > It is already possible to read the MAC address via a NVMEM provider. But
>> > there are boards, esp. with many ports, which only have a base MAC
>> > address stored. Thus we need to have a way to provide an offset per
>> > network device.
>> 
>> We need to see what Rob thinks of this. There was recently a patchset
>> to support swapping the byte order of the MAC address in a NVMEM. Rob
>> said the NVMEM provider should have the property, not the MAC driver.
>> This does seems more ethernet specific, so maybe it should be an
>> Ethernet property?
> 
> There was also this one[1]. I'm not totally opposed, but don't want to
> see a never ending addition of properties to try to describe any
> possible transformation.

Agreed, that stuff like ASCII MAC address parsing should be done
elsewhere. But IMHO adding an offset is a pretty common one (as also
pointed out in [1]). And it also need to be a per ethernet device
property.

-michael

[1] 
https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20200920095724.8251-4-ansuelsmth@gmail.com/