[PATCH] stmmac: Don't exit mdio registration when mdio subnode is not found in the DTS

[Florian Fainelli]

On December 29, 2015 6:05:35 AM PST, Romain Perier <romain.perier at gmail.com> wrote:
>Originally, most of the platforms using this driver did not define an
>mdio subnode
>in the devicetree. Commit e34d65 ("stmmac: create of compatible mdio
>bus for stmmac driver")
>introduced a backward compatibily issue by using of_mdiobus_register
>explicitly
>with an mdio subnode. This patch fixes the issue by calling the
>function
>mdiobus_register, when mdio subnode is not found. The driver is now
>compatible
>with both modes.

Looks reasonable to me, though you will want to make sure the different DTSes get updated to include the proper compatible node for the MDIO bus.

>
>Signed-off-by: Romain Perier <romain.perier at gmail.com>

Please include a Fixes tag to help keep track of changes.

>---
> drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>index 16c85cc..0034de44 100644
>--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>@@ -218,8 +218,7 @@ int stmmac_mdio_register(struct net_device *ndev)
> 		if (mdio_node) {
> 			netdev_dbg(ndev, "FOUND MDIO subnode\n");
> 		} else {
>-			netdev_err(ndev, "NO MDIO subnode\n");
>-			return 0;
>+			netdev_warn(ndev, "No MDIO subnode found\n");
> 		}
> 	}
> 
>@@ -251,7 +250,10 @@ int stmmac_mdio_register(struct net_device *ndev)
> 	new_bus->phy_mask = mdio_bus_data->phy_mask;
> 	new_bus->parent = priv->device;
> 
>-	err = of_mdiobus_register(new_bus, mdio_node);
>+	if (IS_ENABLED(CONFIG_OF) && mdio_node)

You should be able to drop the IS_ENABLED part since there is an inline provided in the non-OF case which does a fallback to mdiobus_register().

>+		err = of_mdiobus_register(new_bus, mdio_node);
>+	else
>+		err = mdiobus_register(new_bus);
> 	if (err != 0) {

This looks reasonable, does it work if we just assign mdio_node to the pdev->dev.of_node to be backwards compatible with DTSes which have not yet been updated?

> 		pr_err("%s: Cannot register as MDIO bus\n", new_bus->name);
> 		goto bus_register_fail;


-- 
Florian