Aw: Re: [PATCH 4/5] arm: dts: mt7623: mux phy0 on Bananapi BPI-R2

[Arınç ÜNAL]

On 31.01.2023 19:39, Frank Wunderlich wrote:
> Hi
>> Gesendet: Dienstag, 31. Januar 2023 um 12:55 Uhr
>> Von: "Matthias Brugger" <matthias.bgg at gmail.com>
>> An: "Arınç ÜNAL" <arinc.unal at arinc9.com>, frank-w at public-files.de, "Rob Herring" <robh+dt at kernel.org>, "Krzysztof Kozlowski" <krzysztof.kozlowski+dt at linaro.org>
>> Cc: devicetree at vger.kernel.org, linux-arm-kernel at lists.infradead.org, linux-mediatek at lists.infradead.org, linux-kernel at vger.kernel.org, erkin.bozoglu at xeront.com, "Sean Wang" <sean.wang at mediatek.com>, "DENG Qingfang" <dqfext at gmail.com>
>> Betreff: Re: [PATCH 4/5] arm: dts: mt7623: mux phy0 on Bananapi BPI-R2
>>
>>
>>
>> On 25/01/2023 17:54, Arınç ÜNAL wrote:
>>> On 25.01.2023 19:41, Frank Wunderlich wrote:
>>>> Am 20. Januar 2023 21:53:17 MEZ schrieb "Arınç ÜNAL" <arinc.unal at arinc9.com>:
>>>>
>>>>>          switch at 1f {
>>>>>              compatible = "mediatek,mt7530";
>>>>>              reg = <0x1f>;
>>>>> @@ -199,11 +208,6 @@ ports {
>>>>>                  #address-cells = <1>;
>>>>>                  #size-cells = <0>;
>>>>>
>>>>> -                port at 0 {
>>>>> -                    reg = <0>;
>>>>> -                    label = "wan";
>>>>> -                };
>>>>> -
>>>>
>>>> This will break existing userspace setups using wan as interface name.
>>>
>>> Yup. The OS being used will have to either rename the interface or adapt to the
>>> new name, eth1.
>>>
>>
>> In that case please explain in the commit message why this is needed. We are
>> trying really hard to not break userspace by a device-tree update.
> 
> I understand the reason why Arınç wants to change it:
> 
> currently all ports including wan-port are routed via dsa over gmac0 (trgmii), Arınç enables the second gmac and port5 of switch to route wan-traffic over the other gmac. But unfortunately there is no mainline-way to rename the gmac1 interface (eth1) to wan...this would be a way to not break the userspace.
> 
> i had an older patch for mtk_eth_soc [1] which do it at driver level for mediatek ethernet driver, but afair a generic way to (re)name interfaces in dts (vendor independ) was requested as the right way.
> 
> regards Frank
> 
> [1] https://github.com/frank-w/BPI-Router-Linux/commit/5088c9c81e90014622a950fca38cfb29e0421155

I tried this [0] before. It's not going to happen on mainline, and 
that's fine. I'll just clearly mention on the patch log that the 
interface name will change with this patch.

[0] 
https://lore.kernel.org/netdev/20220404114000.3549-1-arinc.unal@arinc9.com/t/#u

Arınç