From: Vladimir Oltean Date: Thu, 4 Jan 2024 14:00:31 +0000 (+0200) Subject: net: dsa: qca8k: put MDIO bus OF node on qca8k_mdio_register() failure X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=68e1010cda7967cfca9c8650ee1f4efcae54ab90;p=linux.git net: dsa: qca8k: put MDIO bus OF node on qca8k_mdio_register() failure 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 Reviewed-by: Alvin Šipraga Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- diff --git a/drivers/net/dsa/qca/qca8k-8xxx.c b/drivers/net/dsa/qca/qca8k-8xxx.c index ec57d9d52072f..5f47a290bd6ef 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->user_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 user 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 user 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