Subject: Re: [PATCH net-next 0/2] net: mdio: add amlogic gxl mdio mux support

From: Andrew Lunn <[email-masked]>
Date: Wed, 18 Jan 2023 04:08:08 +0100

On Mon, Jan 16, 2023 at 10:16:34AM +0100, Jerome Brunet wrote:
> Add support for the MDIO multiplexer found in the Amlogic GXL SoC family.
> This multiplexer allows to choose between the external (SoC pins) MDIO bus,
> or the internal one leading to the integrated 10/100M PHY.
> 
> This multiplexer has been handled with the mdio-mux-mmioreg generic driver
> so far. When it was added, it was thought the logic was handled by a
> single register.
> 
> It turns out more than a single register need to be properly set.
> As long as the device is using the Amlogic vendor bootloader, or upstream
> u-boot with net support, it is working fine since the kernel is inheriting
> the bootloader settings. Without net support in the bootloader, this glue
> comes unset in the kernel and only the external path may operate properly.
> 
> With this driver (and the associated DT update), the kernel no longer relies
> on the bootloader to set things up, fixing the problem.

Ideally, you should also post an actual user of this driver, i.e. the
DT updates.

> This has been tested on the aml-s905x-cc (LePotato) for the internal path
> and the aml-s912-pc (Tartiflette) for the external path.

So these exist in mainline, which is enough for me.

   Andrew