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

[Rafał Miłecki]

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.


Does it make sense now? Should I reword this commit somehow?

-- 
Rafał Miłecki