diff mbox series

[net-next,v5,17/20] net: axienet: Fix MDIO bus parent node detection

Message ID 1559860104-927-18-git-send-email-hancock@sedsystems.ca
State Accepted
Delegated to: David Miller
Headers show
Series Xilinx axienet driver updates (v5) | expand

Commit Message

Robert Hancock June 6, 2019, 10:28 p.m. UTC 
This driver was previously using the parent node of the specified PHY
node as the device node to register the MDIO bus on. Andrew Lunn
pointed out this is wrong as the PHY node is potentially not even
underneath the MDIO bus for the current device instance. Find the MDIO
node explicitly by looking it up by name under the controller's device
node instead.

This could potentially break existing device trees if they don't use
"mdio" as the name for the MDIO bus, but I did not find any with various
searches and Xilinx's examples all use mdio as the name so it seems like
this should be relatively safe.

Signed-off-by: Robert Hancock <hancock@sedsystems.ca>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c b/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c
index 7106810..435ed30 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c
@@ -228,7 +228,6 @@  int axienet_mdio_setup(struct axienet_local *lp)
 	if (!bus)
 		return -ENOMEM;
 
-	mdio_node = of_get_parent(lp->phy_node);
 	snprintf(bus->id, MII_BUS_ID_SIZE, "axienet-%.8llx",
 		 (unsigned long long)lp->regs_start);
 
@@ -239,7 +238,9 @@  int axienet_mdio_setup(struct axienet_local *lp)
 	bus->parent = lp->dev;
 	lp->mii_bus = bus;
 
+	mdio_node = of_get_child_by_name(lp->dev->of_node, "mdio");
 	ret = of_mdiobus_register(bus, mdio_node);
+	of_node_put(mdio_node);
 	if (ret) {
 		mdiobus_free(bus);
 		lp->mii_bus = NULL;