On 7/24/20 3:50 AM, Codrin Ciubotariu wrote:
> The MACB embeds an MDIO bus controller. For this reason, the PHY nodes
> were represented as sub-nodes in the MACB node. Generally, the
> Ethernet controller is different than the MDIO controller, so the PHYs
> are probed by a separate MDIO driver. Since adding the PHY nodes directly
> under the ETH node became deprecated, we adjust the MACB driver to look
> for an MDIO node and register the subnode MDIO devices.
>
> Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@xxxxxxxxxxxxx>
> ---
>
> Changes in v3:
> - moved the check for the mdio node at the beginnging of
> macb_mdiobus_register(). This way, the mdio devices will be probed even
> if macb is a fixed-link
>
> Changes in v2:
> - readded newline removed by mistake;
>
> drivers/net/ethernet/cadence/macb_main.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index 89fe7af5e408..cb0b3637651c 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -740,6 +740,16 @@ static int macb_mii_probe(struct net_device *dev)
> static int macb_mdiobus_register(struct macb *bp)
> {
> struct device_node *child, *np = bp->pdev->dev.of_node;
> + struct device_node *mdio_node;
> + int ret;
> +
> + /* if an MDIO node is present, it should contain the PHY nodes */
> + mdio_node = of_get_child_by_name(np, "mdio");
> + if (mdio_node) {
> + ret = of_mdiobus_register(bp->mii_bus, mdio_node);
> + of_node_put(mdio_node);
> + return ret;
> + }
This does take care of registering the MDIO bus controller when present
as a sub-node, however if you also plan on making use of fixed-link, we
will have already returned.
>
> if (of_phy_is_fixed_link(np))
> return mdiobus_register(bp->mii_bus);
>
Really not sure what this is achieving, because we start off assuming
that we have an OF driven configuration, but later on we register the
MDIO bus with mdiobus_register() (and not of_mdiobus_register()), so no
scanning of the MDIO bus will happen.
How does the driver currently support being provided a fixed-link
property? Should not we at least have this pattern:
*/
if (of_phy_is_fixed_link(dn)) {
ret = of_phy_register_fixed_link(dn);
if (ret)
return ret;
priv->phy_dn = dn;
}
It does not look like you are breaking anything here, because it does
not look like this works at all.
--
Florian
