Re: [RFC PATCH v2 11/11] riscv: soc: Allwinner D1 GMAC driver only for temp use

[Arnd Bergmann <arnd@arndb.de>]

On Sun, Jun 6, 2021 at 11:04 AM <guoren@kernel.org> wrote:

> diff --git a/arch/riscv/boot/dts/allwinner/allwinner-d1-nezha-kit.dts b/arch/riscv/boot/dts/allwinner/allwinner-d1-nezha-kit.dts
> index cd9f7c9..31b681d 100644
> --- a/arch/riscv/boot/dts/allwinner/allwinner-d1-nezha-kit.dts
> +++ b/arch/riscv/boot/dts/allwinner/allwinner-d1-nezha-kit.dts
> @@ -11,7 +11,7 @@
>         compatible = "allwinner,d1-nezha-kit";
>
>         chosen {
> -               bootargs = "console=ttyS0,115200";
> +               bootargs = "console=ttyS0,115200 rootwait init=/sbin/init root=/dev/nfs rw nfsroot=192.168.101.200:/tmp/rootfs_nfs,v3,tcp,nolock ip=192.168.101.23";

These are not board specific options, they should be set by the bootloader
according to the network environment. It clearly doens't belong
into this patch .

>                 stdout-path = &serial0;
>         };
>
> diff --git a/arch/riscv/boot/dts/allwinner/allwinner-d1.dtsi b/arch/riscv/boot/dts/allwinner/allwinner-d1.dtsi
> index 11cd938..d317e19 100644
> --- a/arch/riscv/boot/dts/allwinner/allwinner-d1.dtsi
> +++ b/arch/riscv/boot/dts/allwinner/allwinner-d1.dtsi
> @@ -80,5 +80,21 @@
>                         clocks = <&dummy_apb>;
>                         status = "disabled";
>                 };
> +
> +               eth@4500000 {
> +                       compatible = "allwinner,sunxi-gmac";
> +                       reg = <0x00 0x4500000 0x00 0x10000 0x00 0x3000030 0x00 0x04>;
> +                       interrupts-extended = <&plic 0x3e 0x04>;
> +                       interrupt-names = "gmacirq";
> +                       device_type = "gmac0";
> +                       phy-mode = "rgmii";
> +                       use_ephy25m = <0x01>;
> +                       tx-delay = <0x03>;
> +                       rx-delay = <0x03>;
> +                       gmac-power0;
> +                       gmac-power1;
> +                       gmac-power2;
> +                       status = "okay";
> +               };

Before you add this in the dts file, the properties need to be documented in
the binding file. The "allwinner,sunxi-gmac" identifier does not appear to
be specific enough here, and the properties don't match what dwmac uses,
which would make it unnecessarily hard to change to the other driver
later on without breaking compatibility to old dtb files.

> +++ b/drivers/net/ethernet/allwinnertmp/sunxi-gmac-ops.c
> @@ -0,0 +1,690 @@
> +/*
> + * linux/drivers/net/ethernet/allwinner/sunxi_gmac_ops.c
> + *
> + * Copyright © 2016-2018, fuzhaoke
> + *             Author: fuzhaoke <fuzhaoke@allwinnertech.com>
> + *
> + * This file is provided under a dual BSD/GPL license.  When using or
> + * redistributing this file, you may do so under either license.

Are you sure this is the correct copyright information and "fuzhaoke" is
the copyright holder for this file? If this is derived from either the
designware
code or the Linux stmmac driver, the authors should be mentioned,
and the license be compatible with the original license terms.

Andre already commented on the driver quality and code duplication, those are
also show-stoppers, but the unclear license terms and dt binding compatibility
are even stronger reasons to not get anywhere close to this driver.

        Arnd