On Tue, Dec 05, 2023 at 02:31:41PM +0300, Serge Semin wrote: > On Tue, Dec 05, 2023 at 10:49:47AM +0000, Russell King (Oracle) wrote: > > On Tue, Dec 05, 2023 at 01:35:27PM +0300, Serge Semin wrote: > > > If the DW XPCS MDIO devices are either left unmasked for being auto-probed > > > or explicitly registered in the MDIO subsystem by means of the > > > mdiobus_register_board_info() method there is no point in creating the > > > dummy MDIO device instance in order to get the DW XPCS handler since the > > > MDIO core subsystem will create the device during the MDIO bus > > > registration procedure. > > > > > Please reword this overly long sentence. > > Ok. > > > > > If they're left unmasked, what prevents them being created as PHY > > devices? > > Not sure I fully get what you meant. If they are left unmasked the > MDIO-device descriptor will be created by the MDIO subsystem anyway. > What the point in creating another one? Saying what Russell said, in a different way: /* * Return true if the child node is for a phy. It must either: * o Compatible string of "ethernet-phy-idX.X" * o Compatible string of "ethernet-phy-ieee802.3-c45" * o Compatible string of "ethernet-phy-ieee802.3-c22" * o In the white list above (and issue a warning) * o No compatibility string * * A device which is not a phy is expected to have a compatible string * indicating what sort of device it is. */ bool of_mdiobus_child_is_phy(struct device_node *child) So when walking the bus, if a node is found which fits these criteria, its assumed to be a PHY. Anything on the MDIO bus which is not a PHY needs to use a compatible. Andrew
