[PATCH 2/2] arm64: dts: renesas: Drop ethernet-phy-ieee802.3-c22 from PHY compatible string on all RZ boards

[Geert Uytterhoeven]

Hi Marek,

On Sun, Jun 30, 2024 at 5:47 AM Marek Vasut <marex at denx.de> wrote:
> The rtl82xx DT bindings do not require ethernet-phy-ieee802.3-c22
> as the fallback compatible string. There are fewer users of the
> Realtek PHY compatible string with fallback compatible string than
> there are users without fallback compatible string, so drop the
> fallback compatible string from the few remaining users:
>
> $ git grep -ho ethernet-phy-id001c....... | sort | uniq -c
>       1 ethernet-phy-id001c.c816",
>       2 ethernet-phy-id001c.c915",
>       2 ethernet-phy-id001c.c915";
>       5 ethernet-phy-id001c.c916",
>      13 ethernet-phy-id001c.c916";
>
> Reported-by: kernel test robot <lkp at intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202406290316.YvZdvLxu-lkp@intel.com/
> Signed-off-by: Marek Vasut <marex at denx.de>

Thanks for your patch!

> Note: this closes only part of the report

In that case you should use a Link: instead of a Closes: tag?

> --- a/arch/arm64/boot/dts/renesas/cat875.dtsi
> +++ b/arch/arm64/boot/dts/renesas/cat875.dtsi
> @@ -22,8 +22,7 @@ &avb {
>         status = "okay";
>
>         phy0: ethernet-phy at 0 {
> -               compatible = "ethernet-phy-id001c.c915",
> -                            "ethernet-phy-ieee802.3-c22";
> +               compatible = "ethernet-phy-id001c.c915";
>                 reg = <0>;
>                 interrupt-parent = <&gpio2>;
>                 interrupts = <21 IRQ_TYPE_LEVEL_LOW>;

What about moving the PHYs inside an mdio subnode, and removing the
compatible properties instead? That would protect against different
board revisions using different PHYs or PHY revisions.

According to Niklas[1], using an mdio subnode cancels the original
reason (failure to identify the PHY in reset state after unbind/rebind
or kexec) for adding the compatible values[2].

[1] https://lore.kernel.org/linux-renesas-soc/20240625171445.GF3655345@ragnatech.se
[2] commit d45ba2a5f718346e ("arm64: dts: renesas: Add compatible
     properties to RTL8211E Ethernet PHYs").

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds