Re: [PATCH net-next 05/10] net: dsa: qca8k: skip MDIO bus creation if its OF node has status = "disabled"
flat view
From: Alvin Šipraga <hidden>
Date: 2024-01-04 15:44:52
On Thu, Jan 04, 2024 at 04:00:32PM +0200, Vladimir Oltean wrote:
Currently the driver calls the non-OF devm_mdiobus_register() rather than devm_of_mdiobus_register() for this case, but it seems to rather be a confusing coincidence, and not a real use case that needs to be supported.
I am not really sure about the use case, but I always thought that status = "disabled" sort of functions the same as if the node were simply never specified. But with your change, there is a behavioural difference between these two cases: (a) mdio unspecified => register "qca8k-legacy user mii" (b) mdio specified, but status = "disabled" => don't register anything Was this your intention?
quoted hunk ↗ jump to hunk
If the device tree says status = "disabled" for the MDIO bus, we shouldn't need an MDIO bus at all. Instead, just exit as early as possible and do not call any MDIO API. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> --- drivers/net/dsa/qca/qca8k-8xxx.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)diff --git a/drivers/net/dsa/qca/qca8k-8xxx.c b/drivers/net/dsa/qca/qca8k-8xxx.c index 5f47a290bd6e..21e36bc3c015 100644 --- a/drivers/net/dsa/qca/qca8k-8xxx.c +++ b/drivers/net/dsa/qca/qca8k-8xxx.c@@ -949,9 +949,11 @@ qca8k_mdio_register(struct qca8k_priv *priv) struct dsa_switch *ds = priv->ds; struct device_node *mdio; struct mii_bus *bus; - int err; + int err = 0; mdio = of_get_child_by_name(priv->dev->of_node, "mdio"); + if (mdio && !of_device_is_available(mdio)) + goto out; bus = devm_mdiobus_alloc(ds->dev); if (!bus) {@@ -967,7 +969,7 @@ qca8k_mdio_register(struct qca8k_priv *priv) ds->user_mii_bus = bus; /* Check if the devicetree declare the port:phy mapping */ - if (of_device_is_available(mdio)) { + if (mdio) { bus->name = "qca8k user mii"; bus->read = qca8k_internal_mdio_read; bus->write = qca8k_internal_mdio_write;@@ -986,7 +988,7 @@ qca8k_mdio_register(struct qca8k_priv *priv) out_put_node: of_node_put(mdio); - +out: return err; }-- 2.34.1