Re: [PATCH 5/5] powerpc: dts: remove label = "cpu" from DSA dt-binding

From: Vladimir Oltean
Date: Sun Dec 04 2022 - 14:00:13 EST


Hi Pali,

On Fri, Dec 02, 2022 at 08:35:52PM +0100, Pali Rohár wrote:
> On Thursday 01 December 2022 17:44:00 Rob Herring wrote:
> > On Thu, Dec 01, 2022 at 06:39:02PM +0100, Pali Rohár wrote:
> > > I was told by Marek (CCed) that DSA port connected to CPU should have
> > > label "cpu" and not "cpu<number>". Modern way for specifying CPU port is
> > > by defining reference to network device, which there is already (&enet1
> > > and &enet0). So that change just "fixed" incorrect naming cpu0 and cpu1.
> > >
> > > So probably linux kernel does not need label = "cpu" in DTS anymore. But
> > > this is not the reason to remove this property. Linux kernel does not
> > > use lot of other nodes and properties too... Device tree should describe
> > > hardware and not its usage in Linux. "label" property is valid in device
> > > tree and it exactly describes what or where is this node connected. And
> > > it may be used for other systems.
> > >
> > > So I do not see a point in removing "label" properties from turris1x.dts
> > > file, nor from any other dts file.
> >
> > Well, it seems like a bit of an abuse of 'label' to me. 'label' should
> > be aligned with a sticker or other identifier identifying something to a
> > human. Software should never care what the value of 'label' is.
>
> But it already does. "label" property is used for setting (initial)
> network interface name for DSA drivers. And you can try to call e.g.
> git grep '"cpu"' net/dsa drivers/net/dsa to see that cpu is still
> present on some dsa places (probably relict or backward compatibility
> before eth reference).

Can you try to eliminate the word "probably" from the information you
transmit and be specific about when did the DSA binding parse or require
the 'label = "cpu"' property for CPU ports in any way?