linux-kernel - [PATCH net-next 3/3] net: mdio: improve reset handling in mdio

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Message-ID: <11b197641e5498cab3e43f8983120fcabe06257e.1761909948.git.buday.csaba@prolan.hu>
Date: Fri, 31 Oct 2025 12:32:28 +0100
From: Buday Csaba <buday.csaba@...lan.hu>
To: Andrew Lunn <andrew@...n.ch>, Heiner Kallweit <hkallweit1@...il.com>,
	Russell King <linux@...linux.org.uk>, "David S. Miller"
	<davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski
	<kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, Philipp Zabel
	<p.zabel@...gutronix.de>, <netdev@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
CC: Buday Csaba <buday.csaba@...lan.hu>
Subject: [PATCH net-next 3/3] net: mdio: improve reset handling in mdio_device.c

Change fwnode_property_read_u32() in mdio_device_register_reset()
to device_property_read_u32(), which is more appropriate here.

Fix a potential leak in mdio_device_register_reset() if both
a reset-gpio and a reset-controller are present.

Make mdio_device_unregister_reset() truly reverse
mdio_device_register_reset() by setting the internal fields to
their default values.

Signed-off-by: Buday Csaba <buday.csaba@...lan.hu>
---
 drivers/net/phy/mdio_device.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/net/phy/mdio_device.c b/drivers/net/phy/mdio_device.c
index ec0263264..2de401961 100644
--- a/drivers/net/phy/mdio_device.c
+++ b/drivers/net/phy/mdio_device.c
@@ -139,15 +139,18 @@ int mdio_device_register_reset(struct mdio_device *mdiodev)
 		gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset");
 
 	reset = reset_control_get_optional_exclusive(&mdiodev->dev, "phy");
-	if (IS_ERR(reset))
+	if (IS_ERR(reset)) {
+		gpiod_put(mdiodev->reset_gpio);
+		mdiodev->reset_gpio = NULL;
 		return PTR_ERR(reset);
+	}
 
 	mdiodev->reset_ctrl = reset;
 
 	/* Read optional firmware properties */
-	fwnode_property_read_u32(dev_fwnode(&mdiodev->dev), "reset-assert-us",
+	device_property_read_u32(&mdiodev->dev, "reset-assert-us",
 				 &mdiodev->reset_assert_delay);
-	fwnode_property_read_u32(dev_fwnode(&mdiodev->dev), "reset-deassert-us",
+	device_property_read_u32(&mdiodev->dev, "reset-deassert-us",
 				 &mdiodev->reset_deassert_delay);
 
 	return 0;
@@ -161,7 +164,11 @@ int mdio_device_register_reset(struct mdio_device *mdiodev)
 void mdio_device_unregister_reset(struct mdio_device *mdiodev)
 {
 	gpiod_put(mdiodev->reset_gpio);
+	mdiodev->reset_gpio = NULL;
 	reset_control_put(mdiodev->reset_ctrl);
+	mdiodev->reset_ctrl = NULL;
+	mdiodev->reset_assert_delay = 0;
+	mdiodev->reset_deassert_delay = 0;
 }
 
 void mdio_device_reset(struct mdio_device *mdiodev, int value)
-- 
2.39.5