This is a note to let you know that I've just added the patch titled
net: dsa: qca8k: put MDIO bus OF node on qca8k_mdio_register() failure
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-dsa-qca8k-put-mdio-bus-of-node-on-qca8k_mdio_reg.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f9b65aae90cecaaded0816e7046e55ad8911c153
Author: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Date: Thu Jan 4 16:00:31 2024 +0200
net: dsa: qca8k: put MDIO bus OF node on qca8k_mdio_register() failure
[ Upstream commit 68e1010cda7967cfca9c8650ee1f4efcae54ab90 ]
of_get_child_by_name() gives us an OF node with an elevated refcount,
which should be dropped when we're done with it. This is so that,
if (of_node_check_flag(node, OF_DYNAMIC)) is true, the node's memory can
eventually be freed.
There are 2 distinct paths to be considered in qca8k_mdio_register():
- devm_of_mdiobus_register() succeeds: since commit 3b73a7b8ec38 ("net:
mdio_bus: add refcounting for fwnodes to mdiobus"), the MDIO core
treats this well.
- devm_of_mdiobus_register() or anything up to that point fails: it is
the duty of the qca8k driver to release the OF node.
This change addresses the second case by making sure that the OF node
reference is not leaked.
The "mdio" node may be NULL, but of_node_put(NULL) is safe.
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Reviewed-by: Alvin Šipraga <alsi@xxxxxxxxxxxxxxx>
Reviewed-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/dsa/qca/qca8k-8xxx.c b/drivers/net/dsa/qca/qca8k-8xxx.c
index 4ce68e655a63..368d53d3b1d6 100644
--- a/drivers/net/dsa/qca/qca8k-8xxx.c
+++ b/drivers/net/dsa/qca/qca8k-8xxx.c
@@ -949,10 +949,15 @@ qca8k_mdio_register(struct qca8k_priv *priv)
struct dsa_switch *ds = priv->ds;
struct device_node *mdio;
struct mii_bus *bus;
+ int err;
+
+ mdio = of_get_child_by_name(priv->dev->of_node, "mdio");
bus = devm_mdiobus_alloc(ds->dev);
- if (!bus)
- return -ENOMEM;
+ if (!bus) {
+ err = -ENOMEM;
+ goto out_put_node;
+ }
bus->priv = (void *)priv;
snprintf(bus->id, MII_BUS_ID_SIZE, "qca8k-%d.%d",
@@ -962,12 +967,12 @@ qca8k_mdio_register(struct qca8k_priv *priv)
ds->slave_mii_bus = bus;
/* Check if the devicetree declare the port:phy mapping */
- mdio = of_get_child_by_name(priv->dev->of_node, "mdio");
if (of_device_is_available(mdio)) {
bus->name = "qca8k slave mii";
bus->read = qca8k_internal_mdio_read;
bus->write = qca8k_internal_mdio_write;
- return devm_of_mdiobus_register(priv->dev, bus, mdio);
+ err = devm_of_mdiobus_register(priv->dev, bus, mdio);
+ goto out_put_node;
}
/* If a mapping can't be found the legacy mapping is used,
@@ -976,7 +981,13 @@ qca8k_mdio_register(struct qca8k_priv *priv)
bus->name = "qca8k-legacy slave mii";
bus->read = qca8k_legacy_mdio_read;
bus->write = qca8k_legacy_mdio_write;
- return devm_mdiobus_register(priv->dev, bus);
+
+ err = devm_mdiobus_register(priv->dev, bus);
+
+out_put_node:
+ of_node_put(mdio);
+
+ return err;
}
static int
