net: phy: at803x: Use a helper to check for phy reset existence

[PATCH net-next] net: phy: at803x: Use a helper to check for phy reset existence

Posted by Maxime Chevallier 1 week, 3 days ago

The at803x family of devices are subjected to an errata that requires
hard-reseting the PHY upon link change.

That can only work if there's a physical reset line wired to the PHY,
which the driver checks by looking if there's a reset GPIO configured
for the MDIO device.

The reset may however be controlled through a reset controller, which
isn't accounted for in the errata handling.

Besides that, PHY drivers aren't expected to directly access the
mdiodev's resources directly, let's therefore wrap this with a phylib
helper, that uses a similar mdio helper to check for reset existence.

This was found in preparation for bus-level resource management for
better mdio scan support.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/phy/qcom/at803x.c | 2 +-
 include/linux/mdio.h          | 5 +++++
 include/linux/phy.h           | 5 +++++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/qcom/at803x.c b/drivers/net/phy/qcom/at803x.c
index ba4dc07752b6..6872dbf77856 100644
--- a/drivers/net/phy/qcom/at803x.c
+++ b/drivers/net/phy/qcom/at803x.c
@@ -537,7 +537,7 @@ static void at803x_link_change_notify(struct phy_device *phydev)
 	 * in the FIFO. In such cases, the FIFO enters an error mode it
 	 * cannot recover from by software.
 	 */
-	if (phydev->state == PHY_NOLINK && phydev->mdio.reset_gpio) {
+	if (phydev->state == PHY_NOLINK && phy_device_has_reset(phydev)) {
 		struct at803x_context context;
 
 		at803x_context_save(phydev, &context);
diff --git a/include/linux/mdio.h b/include/linux/mdio.h
index 300805e66592..a7d9e3ae362a 100644
--- a/include/linux/mdio.h
+++ b/include/linux/mdio.h
@@ -86,6 +86,11 @@ static inline void *mdiodev_get_drvdata(struct mdio_device *mdio)
 	return dev_get_drvdata(&mdio->dev);
 }
 
+static inline bool mdiodev_has_reset(struct mdio_device *mdio)
+{
+	return (mdio->reset_gpio || mdio->reset_ctrl);
+}
+
 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);
diff --git a/include/linux/phy.h b/include/linux/phy.h
index fc680901275b..beff1d6fcc7c 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -2231,6 +2231,11 @@ static inline void phy_device_reset(struct phy_device *phydev, int value)
 	mdio_device_reset(&phydev->mdio, value);
 }
 
+static inline bool phy_device_has_reset(struct phy_device *phydev)
+{
+	return mdiodev_has_reset(&phydev->mdio);
+}
+
 #define phydev_err(_phydev, format, args...)	\
 	dev_err(&_phydev->mdio.dev, format, ##args)
 
-- 
2.55.0

Re: [PATCH net-next] net: phy: at803x: Use a helper to check for phy reset existence

Posted by Nicolai Buchwitz 1 week, 2 days ago

Hi Maxime 

On July 15, 2026 12:13:54 PM GMT+02:00, Maxime Chevallier <maxime.chevallier@bootlin.com> wrote:
>The at803x family of devices are subjected to an errata that requires
>hard-reseting the PHY upon link change.
>
>That can only work if there's a physical reset line wired to the PHY,
>which the driver checks by looking if there's a reset GPIO configured
>for the MDIO device.
>
>The reset may however be controlled through a reset controller, which
>isn't accounted for in the errata handling.
>
>Besides that, PHY drivers aren't expected to directly access the
>mdiodev's resources directly, let's therefore wrap this with a phylib
>helper, that uses a similar mdio helper to check for reset existence.
>
>This was found in preparation for bus-level resource management for
>better mdio scan support.
>
>Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
>---
> drivers/net/phy/qcom/at803x.c | 2 +-
> include/linux/mdio.h          | 5 +++++
> include/linux/phy.h           | 5 +++++
> 3 files changed, 11 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/net/phy/qcom/at803x.c b/drivers/net/phy/qcom/at803x.c
>index ba4dc07752b6..6872dbf77856 100644
>--- a/drivers/net/phy/qcom/at803x.c
>+++ b/drivers/net/phy/qcom/at803x.c
>@@ -537,7 +537,7 @@ static void at803x_link_change_notify(struct phy_device *phydev)
> 	 * in the FIFO. In such cases, the FIFO enters an error mode it
> 	 * cannot recover from by software.
> 	 */
>-	if (phydev->state == PHY_NOLINK && phydev->mdio.reset_gpio) {
>+	if (phydev->state == PHY_NOLINK && phy_device_has_reset(phydev)) {
> 		struct at803x_context context;
> 
> 		at803x_context_save(phydev, &context);
>diff --git a/include/linux/mdio.h b/include/linux/mdio.h
>index 300805e66592..a7d9e3ae362a 100644
>--- a/include/linux/mdio.h
>+++ b/include/linux/mdio.h
>@@ -86,6 +86,11 @@ static inline void *mdiodev_get_drvdata(struct mdio_device *mdio)
> 	return dev_get_drvdata(&mdio->dev);
> }
> 
>+static inline bool mdiodev_has_reset(struct mdio_device *mdio)
>+{
>+	return (mdio->reset_gpio || mdio->reset_ctrl);
>+}
>+
> 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);
>diff --git a/include/linux/phy.h b/include/linux/phy.h
>index fc680901275b..beff1d6fcc7c 100644
>--- a/include/linux/phy.h
>+++ b/include/linux/phy.h
>@@ -2231,6 +2231,11 @@ static inline void phy_device_reset(struct phy_device *phydev, int value)
> 	mdio_device_reset(&phydev->mdio, value);
> }
> 
>+static inline bool phy_device_has_reset(struct phy_device *phydev)
>+{
>+	return mdiodev_has_reset(&phydev->mdio);
>+}
>+
> #define phydev_err(_phydev, format, args...)	\
> 	dev_err(&_phydev->mdio.dev, format, ##args)
> 

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>

Thanks,
Nicolai

Re: [PATCH net-next] net: phy: at803x: Use a helper to check for phy reset existence

Posted by Andrew Lunn 1 week, 3 days ago

On Wed, Jul 15, 2026 at 12:13:54PM +0200, Maxime Chevallier wrote:
> The at803x family of devices are subjected to an errata that requires
> hard-reseting the PHY upon link change.
> 
> That can only work if there's a physical reset line wired to the PHY,
> which the driver checks by looking if there's a reset GPIO configured
> for the MDIO device.
> 
> The reset may however be controlled through a reset controller, which
> isn't accounted for in the errata handling.
> 
> Besides that, PHY drivers aren't expected to directly access the
> mdiodev's resources directly, let's therefore wrap this with a phylib
> helper, that uses a similar mdio helper to check for reset existence.
> 
> This was found in preparation for bus-level resource management for
> better mdio scan support.
> 
> Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew