Hi Andrew,
You're right that the xpcs core uses C45 exclusively, and modern kernels
no longer require C22 callbacks for mdiobus_register().
However, I'd prefer to keep them for two reasons:
1. Debugging tools (mdio-tools, ethtool, etc.) often use C22 reads to
inspect PHY/PCS registers. Having these callbacks makes debugging
much easier without having to patch the driver.
2. It keeps the driver consistent with pcs-xpcs-plat.c, which also
provides both C22 and C45 callbacks even though the xpcs core
only uses C45.
If you strongly prefer removing them to keep the code minimal, I can do
that in v3. But I think the debug benefit justifies keeping them.
Keep them. I was thinking it side steps the issue of accidentally
mixing up C22 registers and C45 registers. But there are useful use
cases for C22.
Andrew