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

[Andrew Lunn]

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.

     Andrew