AW: [PATCH 3/9] net: mdio: realtek-rtl9300: Add ports to info structure

["Markus Stockhausen" <markus.stockhausen@gmx.de>]

> Von: Andrew Lunn <andrew@lunn.ch> 
> Gesendet: Dienstag, 19. Mai 2026 22:14
> An: Markus Stockhausen <markus.stockhausen@gmx.de>
> Betreff: Re: [PATCH 3/9] net: mdio: realtek-rtl9300: Add ports to info
structure
> .
> > Where does this come from?
> > 
> > - The hardware has 1-4 SMI busses
> > - Each bus serves up to 32 addresses
> > - A switch has X physical ports
> > - The mdio controller can only be fed with "physical port"
>
> So in general, the MDIO API uses an address in the range 0-31, as
> defined in C22/C45. I would try to do any sort of mapping of ports to
> MDIO addresses in a layer above MDIO. Maybe that is not possible, i
> only partially remember the discussion about this hardware. But if it
> is going to get more complex, i really would suggest pulling it out
> into a layer above, and let the MDIO driver simply do MDIO.

Having spent a few months to get all this sorted out I can
say that the port concept is quite easy to understand and
is already quite simple implemented. One only needs to know 
the chain

bus/address -> port -> bus/address 

Current upstream codes uses 220 lines of code for only one 
target. Downstream serves 4 devices with same quality and
error handling with the following metrics:

- 80 lines of code for central command runner
- 160 lines for all 16 SOC specific read/read_c45/write/write_c45 functions
- 80 lines of code for 4 generic command feeder functions

I finally want to add myself as maintainer for the driver.
Just in case that helps for the descision.  

Markus