> In reality, it is not the PHY having register in MMS12, and not even > the MAC. These are really "chip-specific" registers, unrelated to > networking (e.g., GPIOs, HW diagnostics, etc.). Having a GPIO driver within the MAC driver is O.K. For hardware diagnostics you should be using devlink, which many MAC drivers have. So i don't see a need for the PHY driver to access MMS 12. Anyway, we can do a real review when you post your code. > Although, I think it is a good idea anyway to allow the MACPHY > drivers to hook into / extend the MDIO access functions. If > anything, because of the hacks you mentioned. But also to allow > vendor-specific extensions. But we don't want vendor specific extensions. OS 101, the OS is there to make all hardware look the same. And in general, it is not often that vendors actually come up with anything unique. And if they do, and it is useful, other vendors will copy it. So rather than doing vendor specific extensions, you should be thinking about how to export it in a way which is common across multiple vendors. Andrew