RE: [PATCH net V2 1/1] net: phy: fix invalid phy id when probe using C22

On Fri, Mar 19, 2021 at 04:56PM +0800, Russell King - ARM Linux admin wrote:

On Fri, Mar 19, 2021 at 08:40:45AM +0100, Heiner Kallweit wrote:

quoted

Is there a specific reason why c22 is probed first? Reversing the order
would solve the issue we speak about here.
c45-probing of c22-only PHY's shouldn't return false positives
(at least at a first glance).

That would likely cause problems for the I2f MDIO driver, since a
C45 read is indistinguishable from a C22 write on the I2C bus.

Hi Russell,

STMMAC is capable of supporting external PHYs that accessible using 
C22 or C45. 

Accordng to patch [1] send earlier, it should solve the problem.

As for any other drivers, if it is not using MDIOBUS_C45_C22, 
It should still work as it is by using MDIOBUS_C22.

[1] https://lkml.org/lkml/2020/11/9/443

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