netdev - [PATCH net-next v1] net: macb: avoid redundant lookup for "mdio" child node in MDIO setup

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Message-Id: <20241030085224.2632426-1-o.rempel@pengutronix.de>
Date: Wed, 30 Oct 2024 09:52:24 +0100
From: Oleksij Rempel <o.rempel@...gutronix.de>
To: Nicolas Ferre <nicolas.ferre@...rochip.com>,
	Claudiu Beznea <claudiu.beznea@...rochip.com>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	Paolo Abeni <pabeni@...hat.com>
Cc: Oleksij Rempel <o.rempel@...gutronix.de>,
	kernel@...gutronix.de,
	linux-kernel@...r.kernel.org,
	netdev@...r.kernel.org,
	havasi@....de
Subject: [PATCH net-next v1] net: macb: avoid redundant lookup for "mdio" child node in MDIO setup

Pass the "mdio" child node directly to `macb_mdiobus_register` to avoid
performing the node lookup twice.

Signed-off-by: Oleksij Rempel <o.rempel@...gutronix.de>
---
 drivers/net/ethernet/cadence/macb_main.c | 23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index ebe886b988917..daa416fb1724e 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -915,20 +915,15 @@ static int macb_mii_probe(struct net_device *dev)
 	return 0;
 }

-static int macb_mdiobus_register(struct macb *bp)
+static int macb_mdiobus_register(struct macb *bp, struct device_node *mdio_np)
 {
 	struct device_node *child, *np = bp->pdev->dev.of_node;

 	/* If we have a child named mdio, probe it instead of looking for PHYs
 	 * directly under the MAC node
 	 */
-	child = of_get_child_by_name(np, "mdio");
-	if (child) {
-		int ret = of_mdiobus_register(bp->mii_bus, child);
-
-		of_node_put(child);
-		return ret;
-	}
+	if (mdio_np)
+		return of_mdiobus_register(bp->mii_bus, mdio_np);

 	/* Only create the PHY from the device tree if at least one PHY is
 	 * described. Otherwise scan the entire MDIO bus. We do this to support
@@ -950,17 +945,15 @@ static int macb_mdiobus_register(struct macb *bp)

 static int macb_mii_init(struct macb *bp)
 {
-	struct device_node *child, *np = bp->pdev->dev.of_node;
+	struct device_node *mdio_np, *np = bp->pdev->dev.of_node;
 	int err = -ENXIO;

 	/* With fixed-link, we don't need to register the MDIO bus,
 	 * except if we have a child named "mdio" in the device tree.
 	 * In that case, some devices may be attached to the MACB's MDIO bus.
 	 */
-	child = of_get_child_by_name(np, "mdio");
-	if (child)
-		of_node_put(child);
-	else if (of_phy_is_fixed_link(np))
+	mdio_np = of_get_child_by_name(np, "mdio");
+	if (!mdio_np && of_phy_is_fixed_link(np))
 		return macb_mii_probe(bp->dev);

 	/* Enable management port */
@@ -984,7 +977,7 @@ static int macb_mii_init(struct macb *bp)

 	dev_set_drvdata(&bp->dev->dev, bp->mii_bus);

-	err = macb_mdiobus_register(bp);
+	err = macb_mdiobus_register(bp, mdio_np);
 	if (err)
 		goto err_out_free_mdiobus;

@@ -999,6 +992,8 @@ static int macb_mii_init(struct macb *bp)
 err_out_free_mdiobus:
 	mdiobus_free(bp->mii_bus);
 err_out:
+	of_node_put(mdio_np);
+
 	return err;
 }

--
2.39.5