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

[Frank Wunderlich]

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