From a77f4f70fd34ac7b67581fe5b89ddc1c9ac20d39 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Thu, 28 Apr 2016 16:24:12 -0700 Subject: [PATCH] of: of_mdio: Check if MDIO bus controller is available Add a check whether the 'struct device_node' pointer passed to of_mdiobus_register() is an available (aka enabled) node in the Device Tree. Rationale for doing this are cases where an Ethernet MAC provides a MDIO bus controller and node, and an additional Ethernet MAC might be connecting its PHY/switches to that first MDIO bus controller, while still embedding one internally which is therefore marked as "disabled". Instead of sprinkling checks like these in callers of of_mdiobus_register(), do this in a central location. Reviewed-by: Andrew Lunn Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/of/of_mdio.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c index b622b33dbf93..e051e1b57609 100644 --- a/drivers/of/of_mdio.c +++ b/drivers/of/of_mdio.c @@ -209,6 +209,10 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np) bool scanphys = false; int addr, rc; + /* Do not continue if the node is disabled */ + if (!of_device_is_available(np)) + return -ENODEV; + /* Mask out all PHYs from auto probing. Instead the PHYs listed in * the device tree are populated after the bus has been registered */ mdio->phy_mask = ~0;