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Date:   Thu, 1 Dec 2022 18:39:02 +0100
From:   Pali =?utf-8?B?Um9ow6Fy?= <pali@kernel.org>
To:     Michael Ellerman <mpe@ellerman.id.au>
Cc:     =?utf-8?B?QXLEsW7DpyDDnE5BTA==?= <arinc.unal@arinc9.com>,
        netdev@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        Marek =?utf-8?B?QmVow7pu?= <kabel@kernel.org>
Subject: Re: [PATCH 5/5] powerpc: dts: remove label = "cpu" from DSA
 dt-binding
Message-ID: <20221201173902.zrtpeq4mkk3i3vpk@pali>
References: <20221130141040.32447-1-arinc.unal@arinc9.com>
 <20221130141040.32447-6-arinc.unal@arinc9.com>
 <87a647s8zg.fsf@mpe.ellerman.id.au>
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On Thursday 01 December 2022 21:40:03 Michael Ellerman wrote:
> Arınç ÜNAL <arinc.unal@arinc9.com> writes:
> > This is not used by the DSA dt-binding, so remove it from all devicetrees.
> >
> > Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
> > ---
> >  arch/powerpc/boot/dts/turris1x.dts | 2 --
> >  1 file changed, 2 deletions(-)
> 
> Adding Pali to Cc.
> 
> These were only recently updated in commit:
> 
>   8bf056f57f1d ("powerpc: dts: turris1x.dts: Fix labels in DSA cpu port nodes")
> 
> Which said:
> 
>   DSA cpu port node has to be marked with "cpu" label.
> 
> But if the binding doesn't use them then I'm confused why they needed to
> be updated.
> 
> cheers

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.

> 
> > diff --git a/arch/powerpc/boot/dts/turris1x.dts b/arch/powerpc/boot/dts/turris1x.dts
> > index 045af668e928..3841c8d96d00 100644
> > --- a/arch/powerpc/boot/dts/turris1x.dts
> > +++ b/arch/powerpc/boot/dts/turris1x.dts
> > @@ -147,7 +147,6 @@ ports {
> >  
> >  					port@0 {
> >  						reg = <0>;
> > -						label = "cpu";
> >  						ethernet = <&enet1>;
> >  						phy-mode = "rgmii-id";
> >  
> > @@ -184,7 +183,6 @@ port@5 {
> >  
> >  					port@6 {
> >  						reg = <6>;
> > -						label = "cpu";
> >  						ethernet = <&enet0>;
> >  						phy-mode = "rgmii-id";
> >  
> > -- 
> > 2.34.1