[PATCH 2/2] ARM: dts: BCM5301X: Set fixed-link for extra Netgear R8000 CPU ports

[Florian Fainelli]

On 10/16/23 08:45, Andrew Lunn wrote:
> On Mon, Oct 16, 2023 at 05:36:24PM +0200, Rafał Miłecki wrote:
>> On 2023-10-14 18:50, Andrew Lunn wrote:
>>> On Fri, Oct 13, 2023 at 12:33:14PM +0200, Rafał Miłecki wrote:
>>>> From: Rafał Miłecki <rafal at milecki.pl>
>>>>
>>>> While switch ports 5 and 7 are disabled (vendor designed port 8 to be
>>>> used for CPU traffic) they could be used strictly technically. For
>>>> some
>>>> reason however both those ports need forcing link to be usable.
>>>
>>> This explanation is not making much sense to me.
>>>
>>> I assume this board does not have an RJ45 for these two ports? But
>>> does it have a header so you can access the MII interface?
>>
>> This PATCH as it is requires a basic familiarity with Northstar platform
>> or checking bcm-ns.dtsi.
>>
>> All Northstar (BCM5301X) devices have 3 Ethernet interfaces. 99% of them
>> have:
>> 1. gmac0 connected to port 5
>> 2. gmac1 connected to port 7
>> 3. gmac2 connected to port 8
>> (it's described in bcm-ns.dtsi).
>>
>>
>> Some vendors decide to use gmac0 and switch port 5. They fill NVRAM with
>> MAC for gmac0.
>>
>> Some vendors decide to use gmac2 & port 8. They set MAC for gmac2.
>>
>>
>> Netgear decided to use gmac2 & port 8 for R8000. They fill NVRAM with
>> MAC for gmac2.
>>
>> If you however insist on using gmac0 you could do that. That just
>> requires setting up gmac0 with a custom/random MAC and forcing link for
>> switch ports as described in this PATCH.
> 
> If the ports are not used, you have them set to disabled, why do they
> need a fixed-link? That is what i don't understand yet.

It seems to me like the commit message could be reworded such that:

Even though ports 5 and 7 are disabled and the system is intended to use 
port 8, make it possible for users to experiment with using ports 5 
and/or 7 if they desire so by ensuring that they have the necessary 
'fixed-link' properties to describe the internal connection within the 
SoC between the switch ports and the two Ethernet controllers.

Rafal, does that capture the intent? If so I can amend the commit 
message while applying.
-- 
Florian

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