Re: [PATCH] net: macb: Set MDIO clock divisor for pclk higher than 160MHz

From: Andrew Lunn
Date: Fri Mar 17 2023 - 10:28:30 EST


> I see them existing in all variants of "GEM" controller and the older "MACB"
> uses a different path so I think that we are save enabling these values.

Great. Thanks for checking.

Reviewed-by: Andrew Lunn <andrew@xxxxxxx>

FYI: Documentation/devicetree/bindings/net/mdio.yaml defines:

clock-frequency:
description:
Desired MDIO bus clock frequency in Hz. Values greater than IEEE 802.3
defined 2.5MHz should only be used when all devices on the bus support
the given clock speed.

So you could if you want make the bus speed configurable. Some devices
do work at faster than 2.5MHz, which can be nice if you have a lot of
traffic, e.g. an Ethernet switch, or raw TDR cable test data.

Andrew