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net: mdio: improve reset handling of mdio devices

PATCH Superseded Buday Csaba 2 participants 5 messages Oct 31, 2025 – Nov 6, 2025

Subsystems (3)
Networking Network drivers Ethernet PHY

v1 of 3 Superseded Latest is v3 →

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Buday Csaba

author
#0 lore raw

cover net: mdio: improve reset handling of mdio devices

This patchset refactors and slightly improves the reset handling of mdio_device.

The patches were split from a larger series, dicussed previously in the link below.

Link https://lore.kernel.org/all/[email protected]/ open here

Buday Csaba (3):
net: mdio: move device reset functions to mdio_device.c
net: mdio: common handling of phy device reset properties
net: mdio: improve reset handling in mdio_device.c

 drivers/net/mdio/fwnode_mdio.c |  5 ----
 drivers/net/phy/mdio_bus.c     | 36 ++---------------------
 drivers/net/phy/mdio_device.c  | 53 ++++++++++++++++++++++++++++++++++
 include/linux/mdio.h           |  2 ++
 4 files changed, 57 insertions(+), 39 deletions(-)

base-commit: 0d0eb186421d0886ac466008235f6d9eedaf918e

Signature · 1 line
2.39.5
author
#1 lore raw

PATCH 1/3 net: mdio: move device reset functions to mdio_device.c

The functions mdiobus_register_gpiod() and mdiobus_register_reset() handle the mdio device reset initialization, which belong to mdio_device.c.
Move them from mdio_bus.c to mdio_device.c, and rename them to match the corresponding source file: mdio_device_register_gpio() and mdio_device_register_reset().
Remove 'static' qualifiers and declare them in mdio.h.

Signed-off-by Buday Csaba <[email protected]>
---
 drivers/net/phy/mdio_bus.c    | 31 ++-----------------------------
 drivers/net/phy/mdio_device.c | 27 +++++++++++++++++++++++++++
 include/linux/mdio.h          |  2 ++
 3 files changed, 31 insertions(+), 29 deletions(-)
drivers/net/phy/mdio_bus.c +2 -29
index cad6ed3aa..f23298232 100644
@@ -33,33 +33,6 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/mdio.h>
 
-static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
-{
-	/* Deassert the optional reset signal */
-	mdiodev->reset_gpio = gpiod_get_optional(&mdiodev->dev,
-						 "reset", GPIOD_OUT_LOW);
-	if (IS_ERR(mdiodev->reset_gpio))
-		return PTR_ERR(mdiodev->reset_gpio);
-
-	if (mdiodev->reset_gpio)
-		gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset");
-
-	return 0;
-}
-
-static int mdiobus_register_reset(struct mdio_device *mdiodev)
-{
-	struct reset_control *reset;
-
-	reset = reset_control_get_optional_exclusive(&mdiodev->dev, "phy");
-	if (IS_ERR(reset))
-		return PTR_ERR(reset);
-
-	mdiodev->reset_ctrl = reset;
-
-	return 0;
-}
-
 int mdiobus_register_device(struct mdio_device *mdiodev)
 {
 	int err;

@@ -68,11 +41,11 @@ int mdiobus_register_device(struct mdio_device *mdiodev)
 		return -EBUSY;
 
 	if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
-		err = mdiobus_register_gpiod(mdiodev);
+		err = mdio_device_register_gpiod(mdiodev);
 		if (err)
 			return err;
 
-		err = mdiobus_register_reset(mdiodev);
+		err = mdio_device_register_reset(mdiodev);
 		if (err)
 			return err;
drivers/net/phy/mdio_device.c +27 -0
index f64176e0e..5a78d8624 100644
@@ -118,6 +118,33 @@ void mdio_device_remove(struct mdio_device *mdiodev)
 }
 EXPORT_SYMBOL(mdio_device_remove);
 
+int mdio_device_register_gpiod(struct mdio_device *mdiodev)
+{
+	/* Deassert the optional reset signal */
+	mdiodev->reset_gpio = gpiod_get_optional(&mdiodev->dev,
+						 "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(mdiodev->reset_gpio))
+		return PTR_ERR(mdiodev->reset_gpio);
+
+	if (mdiodev->reset_gpio)
+		gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset");
+
+	return 0;
+}
+
+int mdio_device_register_reset(struct mdio_device *mdiodev)
+{
+	struct reset_control *reset;
+
+	reset = reset_control_get_optional_exclusive(&mdiodev->dev, "phy");
+	if (IS_ERR(reset))
+		return PTR_ERR(reset);
+
+	mdiodev->reset_ctrl = reset;
+
+	return 0;
+}
+
 void mdio_device_reset(struct mdio_device *mdiodev, int value)
 {
 	unsigned int d;
include/linux/mdio.h +2 -0
index 42d6d47e4..1322d2623 100644
@@ -92,6 +92,8 @@ void mdio_device_free(struct mdio_device *mdiodev);
 struct mdio_device *mdio_device_create(struct mii_bus *bus, int addr);
 int mdio_device_register(struct mdio_device *mdiodev);
 void mdio_device_remove(struct mdio_device *mdiodev);
+int mdio_device_register_gpiod(struct mdio_device *mdiodev);
+int mdio_device_register_reset(struct mdio_device *mdiodev);
 void mdio_device_reset(struct mdio_device *mdiodev, int value);
 int mdio_driver_register(struct mdio_driver *drv);
 void mdio_driver_unregister(struct mdio_driver *drv);
Signature · 1 line
2.39.5
author
#2 lore raw

PATCH 2/3 net: mdio: common handling of phy device reset properties

In reply to Buday Csaba

Unify the handling of the per device reset properties for mdio_device.

Merge mdio_device_register_gpiod() and mdio_device_register_reset() into mdio_device_register_reset(), that handles both reset-controllers and reset-gpios.
Move reading of the reset firmware properties (reset-assert-us, reset-deassert-us) from fwnode_mdio.c to mdio_device_register_reset(), so all reset related initialization code is kept in one place.

Introduce mdio_device_unregister_reset() to release the associated resources.

These changes make tracking the reset properties easier. Added kernel-doc for mdio_device_register/unregister_reset().

No functional changes intended.

Signed-off-by Buday Csaba <[email protected]>
---
 drivers/net/mdio/fwnode_mdio.c |  5 -----
 drivers/net/phy/mdio_bus.c     |  7 +------
 drivers/net/phy/mdio_device.c  | 35 ++++++++++++++++++++++++++--------
 include/linux/mdio.h           |  2 +-
 4 files changed, 29 insertions(+), 20 deletions(-)
drivers/net/mdio/fwnode_mdio.c +0 -5
index 9b41d4697..ba7091518 100644
@@ -92,11 +92,6 @@ int fwnode_mdiobus_phy_device_register(struct mii_bus *mdio,
 	if (fwnode_property_read_bool(child, "broken-turn-around"))
 		mdio->phy_ignore_ta_mask |= 1 << addr;
 
-	fwnode_property_read_u32(child, "reset-assert-us",
-				 &phy->mdio.reset_assert_delay);
-	fwnode_property_read_u32(child, "reset-deassert-us",
-				 &phy->mdio.reset_deassert_delay);
-
 	/* Associate the fwnode with the device structure so it
 	 * can be looked up later
 	 */
drivers/net/phy/mdio_bus.c +1 -6
index f23298232..748c6a9aa 100644
@@ -41,10 +41,6 @@ int mdiobus_register_device(struct mdio_device *mdiodev)
 		return -EBUSY;
 
 	if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
-		err = mdio_device_register_gpiod(mdiodev);
-		if (err)
-			return err;
-
 		err = mdio_device_register_reset(mdiodev);
 		if (err)
 			return err;

@@ -64,8 +60,7 @@ int mdiobus_unregister_device(struct mdio_device *mdiodev)
 	if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
 		return -EINVAL;
 
-	gpiod_put(mdiodev->reset_gpio);
-	reset_control_put(mdiodev->reset_ctrl);
+	mdio_device_unregister_reset(mdiodev);
 
 	mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
drivers/net/phy/mdio_device.c +27 -8
index 5a78d8624..ec0263264 100644
@@ -118,8 +118,17 @@ void mdio_device_remove(struct mdio_device *mdiodev)
 }
 EXPORT_SYMBOL(mdio_device_remove);
 
-int mdio_device_register_gpiod(struct mdio_device *mdiodev)
+/**
+ * mdio_device_register_reset - Read and initialize the reset properties of
+ *				an mdio device
+ * @mdiodev: mdio_device structure
+ *
+ * Return: Zero if successful, negative error code on failure
+ */
+int mdio_device_register_reset(struct mdio_device *mdiodev)
 {
+	struct reset_control *reset;
+
 	/* Deassert the optional reset signal */
 	mdiodev->reset_gpio = gpiod_get_optional(&mdiodev->dev,
 						 "reset", GPIOD_OUT_LOW);

@@ -129,22 +138,32 @@ int mdio_device_register_gpiod(struct mdio_device *mdiodev)
 	if (mdiodev->reset_gpio)
 		gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset");
 
-	return 0;
-}
-
-int mdio_device_register_reset(struct mdio_device *mdiodev)
-{
-	struct reset_control *reset;
-
 	reset = reset_control_get_optional_exclusive(&mdiodev->dev, "phy");
 	if (IS_ERR(reset))
 		return PTR_ERR(reset);
 
 	mdiodev->reset_ctrl = reset;
 
+	/* Read optional firmware properties */
+	fwnode_property_read_u32(dev_fwnode(&mdiodev->dev), "reset-assert-us",
+				 &mdiodev->reset_assert_delay);
+	fwnode_property_read_u32(dev_fwnode(&mdiodev->dev), "reset-deassert-us",
+				 &mdiodev->reset_deassert_delay);
+
 	return 0;
 }
 
+/**
+ * mdio_device_unregister_reset - uninitialize the reset properties of
+ *				  an mdio device
+ * @mdiodev: mdio_device structure
+ */
+void mdio_device_unregister_reset(struct mdio_device *mdiodev)
+{
+	gpiod_put(mdiodev->reset_gpio);
+	reset_control_put(mdiodev->reset_ctrl);
+}
+
 void mdio_device_reset(struct mdio_device *mdiodev, int value)
 {
 	unsigned int d;
include/linux/mdio.h +1 -1
index 1322d2623..e76f5a6c2 100644
@@ -92,8 +92,8 @@ void mdio_device_free(struct mdio_device *mdiodev);
 struct mdio_device *mdio_device_create(struct mii_bus *bus, int addr);
 int mdio_device_register(struct mdio_device *mdiodev);
 void mdio_device_remove(struct mdio_device *mdiodev);
-int mdio_device_register_gpiod(struct mdio_device *mdiodev);
 int mdio_device_register_reset(struct mdio_device *mdiodev);
+void mdio_device_unregister_reset(struct mdio_device *mdiodev);
 void mdio_device_reset(struct mdio_device *mdiodev, int value);
 int mdio_driver_register(struct mdio_driver *drv);
 void mdio_driver_unregister(struct mdio_driver *drv);
Signature · 1 line
2.39.5
author
#3 lore raw

PATCH 3/3 net: mdio: improve reset handling in mdio_device.c

In reply to Buday Csaba

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 <[email protected]>
---
 drivers/net/phy/mdio_device.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)
drivers/net/phy/mdio_device.c +10 -3
index ec0263264..2de401961 100644
@@ -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)
Signature · 1 line
2.39.5
maintainer
#4 lore raw

Re: [PATCH net-next 3/3] net: mdio: improve reset handling in mdio_device.c

drivers/net/phy/mdio_device.c int mdio_device_register_reset(struct mdio_device *mdiodev) · line 146

Quoted 7 lines · On Fri, 31 Oct 2025 12:32:28 +0100 Buday Csaba wrote:
drivers/net/phy/mdio_device.c +4 -1
 	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);
+	}

We usually consider all sort of leaks as real fixes. Let's fix this in mdiobus_register_device() in net/main first? Then do the refactoring once net merges into net-next (every Thu)?

Signature · 1 line
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