[PATCH AUTOSEL 6.8 14/68] net: dsa: qca8k: put MDIO controller OF node if unavailable

From: Sasha Levin
Date: Fri Mar 29 2024 - 08:31:32 EST


From: Vladimir Oltean <vladimir.oltean@xxxxxxx>

[ Upstream commit 08932323ccf7f8c4c85db9cb12a791ed81264f66 ]

It was pointed out during the review [1] of commit e66bf63a7f67 ("net:
dsa: qca8k: skip MDIO bus creation if its OF node has status =
"disabled"") that we now leak a reference to the "mdio" OF node if it is
disabled.

This is only a concern when using dynamic OF as far as I can tell (like
probing on an overlay), since OF nodes are never freed in the regular
case. Additionally, I'm unaware of any actual device trees (in
production or elsewhere) which have status = "disabled" for the MDIO OF
node. So handling this as a simple enhancement.

[1] https://lore.kernel.org/netdev/CAJq09z4--Ug+3FAmp=EimQ8HTQYOWOuVon-PUMGB5a1N=RPv4g@xxxxxxxxxxxxxx/

Suggested-by: Luiz Angelo Daros de Luca <luizluca@xxxxxxxxx>
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/dsa/qca/qca8k-8xxx.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/dsa/qca/qca8k-8xxx.c b/drivers/net/dsa/qca/qca8k-8xxx.c
index 7a864329cb726..95d78b3181d1c 100644
--- a/drivers/net/dsa/qca/qca8k-8xxx.c
+++ b/drivers/net/dsa/qca/qca8k-8xxx.c
@@ -954,7 +954,7 @@ qca8k_mdio_register(struct qca8k_priv *priv)

mdio = of_get_child_by_name(dev->of_node, "mdio");
if (mdio && !of_device_is_available(mdio))
- goto out;
+ goto out_put_node;

bus = devm_mdiobus_alloc(dev);
if (!bus) {
@@ -988,7 +988,6 @@ qca8k_mdio_register(struct qca8k_priv *priv)

out_put_node:
of_node_put(mdio);
-out:
return err;
}

--
2.43.0