Re: Failed to reinit phy of spacemit-dwmac when reset-gpio is present

[Maxime Chevallier <maxime.chevallier@bootlin.com>]

Hi Inochi,

On 7/12/26 06:52, Inochi Amaoto wrote:
> TL;DR:
> 
> The DWMAC on Spacemit K3 is failled to register phy after the reload
> the driver module (rmmod then insmod). Because the reset-gpio is
> asserted while unloading the driver and is not desserted before reading
> the c22 id, which leads to a fault.

You're not the first one facing this type of issues, this is a long standing
source of issues. The problem is partially hidden by the fact that often times
the bootloader deals with the PHY reset (like the case you're facing)

Take a look at these discussions :

https://lore.kernel.org/netdev/cover.1761732347.git.buday.csaba@prolan.hu/

and maybe more intersting, Russell suggested an approach on how we could potentially
address this here :

https://lore.kernel.org/all/aTBeVTlsElGXUCSN@shell.armlinux.org.uk/


> ---
> --- a/arch/riscv/boot/dts/spacemit/k3-pico-itx.dts
> +++ b/arch/riscv/boot/dts/spacemit/k3-pico-itx.dts
> @@ -196,7 +196,8 @@ &eth0 {
> 
>  	mdio {
>  		phy0: phy@1 {
> -			compatible = "ethernet-phy-ieee802.3-c22";
> +			compatible = "ethernet-phy-id001c.c916",
> +				     "ethernet-phy-ieee802.3-c22";

Indeed that's merely a workaround :(

Maxime