Re: [PATCH v2 1/3] Revert "ARM: dts: sun7i: A20-olinuxino-lime2: Fix ethernet phy-mode"

[Jernej Škrabec]

Hi Petr!

Dne torek, 15. marec 2022 ob 10:52:42 CET je Petr Štetiar napisal(a):
> This reverts commit 55dd7e059098ce4bd0a55c251cb78e74604abb57 as it
> breaks network on my A20-olinuxino-lime2 hardware revision "K" which has
> Micrel KSZ9031RNXCC-TR Gigabit PHY. Bastien has probably some previous
> hardware revisions which were based on RTL8211E-VB-CG1 PHY and thus this
> fix was working on his board.

NAK.

As Corentin mentioned in another discussion, new DT variant should be 
introduced for newer board model. Otherwise we can play this revert game with 
each new revision which changes Ethernet PHY behaviour. It also makes most 
sense to have naming chronologically sorted. If board name in DT file doesn't 
have any postfix, it should be compatible with earliest publicly available 
board. If board manufacturer releases new board variant with incompatible 
changes, new DT with appropriate postfix should be introduced.

I understand that this is frustrating for you, but whole situation around 
mentioned commit is unfortunate and we can't satisfy everyone.

Also good way to solve such issues is to apply DT overlay in bootloader based 
on board revision number. I know Olimex implemented DT fixup in their 
downstream U-Boot fork.

Best regards,
Jernej

> 
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Bastien Roucariès <rouca@xxxxxxxxxx>
> References: https://github.com/openwrt/openwrt/issues/9153
> References: https://github.com/OLIMEX/OLINUXINO/blob/master/HARDWARE/A20-OLinuXino-LIME2/hardware_revision_changes_log.txt
> Signed-off-by: Petr Štetiar <ynezz@xxxxxxx>
> ---
>  arch/arm/boot/dts/sun7i-a20-olinuxino-lime2.dts | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/boot/dts/sun7i-a20-olinuxino-lime2.dts b/arch/arm/boot/
dts/sun7i-a20-olinuxino-lime2.dts
> index ecb91fb899ff..8077f1716fbc 100644
> --- a/arch/arm/boot/dts/sun7i-a20-olinuxino-lime2.dts
> +++ b/arch/arm/boot/dts/sun7i-a20-olinuxino-lime2.dts
> @@ -112,7 +112,7 @@ &gmac {
>  	pinctrl-names = "default";
>  	pinctrl-0 = <&gmac_rgmii_pins>;
>  	phy-handle = <&phy1>;
> -	phy-mode = "rgmii-id";
> +	phy-mode = "rgmii";
>  	status = "okay";
>  };
>  
>