Re: [PATCH v4 08/11] riscv: milkv_duo_256m: Use upstream devicetree

["Zhuxu Ran" <zhuxu_ran@zohomail.com>]

> I see that milkv_duo_256m_defconfig doesn't enable DM_MDIO, DM_MDIO_MUX
> or MDIO_MUX_MMIOREG, so nothing binds to the mdio-mux node.
>
> Note that the upstream gmac0 node uses phy-mode = "internal" and a
> phy-handle into the mdio mux, while the old local DT used phy-mode =
> "rmii".
>
> Can you check this? Have you tested the ethernet port on Duo 256M?

Hi Hiago,

Thanks for catching this. You are right that the upstream devicetree
requires the DM MDIO mux support.

My earlier Ethernet test passed, but the mdio-mux node was not bound,
so it did not verify the MDIO topology described by the upstream
devicetree.

After enabling CONFIG_DM_MDIO, CONFIG_DM_MDIO_MUX, and
CONFIG_MDIO_MUX_MMIOREG, the MMIO mux, the internal MDIO bus, and the
DesignWare MDIO bus are all probed. I tested this on the Milk-V Duo 256M
after a cold boot; the link negotiated at 100 Mbps full duplex, and both
DHCP and TFTP worked.

I will add these options to milkv_duo_256m_defconfig in the next revision.

-- 
Best regards,
Zhuxu Ran