diff mbox series

[net,v2,1/1] net: usb: smsc95xx: fix external PHY reset

Message ID 20221115114434.9991-2-alexandru.tachici@analog.com (mailing list archive)
State Accepted
Commit 809ff97a677ff85dfb7ce2b63be261d1633dcf29
Delegated to: Netdev Maintainers
Headers show
Series net: usb: smsc95xx: fix external PHY reset | expand

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netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
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Commit Message

Alexandru Tachici Nov. 15, 2022, 11:44 a.m. UTC 
An external PHY needs settling time after power up or reset.
In the bind() function an mdio bus is registered. If at this point
the external PHY is still initialising, no valid PHY ID will be
read and on phy_find_first() the bind() function will fail.

If an external PHY is present, wait the maximum time specified
in 802.3 45.2.7.1.1.

Fixes: 05b35e7eb9a1 ("smsc95xx: add phylib support")
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
---
 drivers/net/usb/smsc95xx.c | 46 ++++++++++++++++++++++++++++++++++----
 1 file changed, 42 insertions(+), 4 deletions(-)

Comments

Andrew Lunn Nov. 16, 2022, 1:46 p.m. UTC | #1 
On Tue, Nov 15, 2022 at 01:44:34PM +0200, Alexandru Tachici wrote:
> An external PHY needs settling time after power up or reset.
> In the bind() function an mdio bus is registered. If at this point
> the external PHY is still initialising, no valid PHY ID will be
> read and on phy_find_first() the bind() function will fail.
> 
> If an external PHY is present, wait the maximum time specified
> in 802.3 45.2.7.1.1.
> 
> Fixes: 05b35e7eb9a1 ("smsc95xx: add phylib support")
> Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>

Thanks for making Russell suggested change.

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

    Andrew
diff mbox series

Patch

diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
index bfb58c91db04..32d2c60d334d 100644
--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -66,6 +66,7 @@  struct smsc95xx_priv {
 	spinlock_t mac_cr_lock;
 	u8 features;
 	u8 suspend_flags;
+	bool is_internal_phy;
 	struct irq_chip irqchip;
 	struct irq_domain *irqdomain;
 	struct fwnode_handle *irqfwnode;
@@ -252,6 +253,43 @@  static void smsc95xx_mdio_write(struct usbnet *dev, int phy_id, int idx,
 	mutex_unlock(&dev->phy_mutex);
 }
 
+static int smsc95xx_mdiobus_reset(struct mii_bus *bus)
+{
+	struct smsc95xx_priv *pdata;
+	struct usbnet *dev;
+	u32 val;
+	int ret;
+
+	dev = bus->priv;
+	pdata = dev->driver_priv;
+
+	if (pdata->is_internal_phy)
+		return 0;
+
+	mutex_lock(&dev->phy_mutex);
+
+	ret = smsc95xx_read_reg(dev, PM_CTRL, &val);
+	if (ret < 0)
+		goto reset_out;
+
+	val |= PM_CTL_PHY_RST_;
+
+	ret = smsc95xx_write_reg(dev, PM_CTRL, val);
+	if (ret < 0)
+		goto reset_out;
+
+	/* Driver has no knowledge at this point about the external PHY.
+	 * The 802.3 specifies that the reset process shall
+	 * be completed within 0.5 s.
+	 */
+	fsleep(500000);
+
+reset_out:
+	mutex_unlock(&dev->phy_mutex);
+
+	return 0;
+}
+
 static int smsc95xx_mdiobus_read(struct mii_bus *bus, int phy_id, int idx)
 {
 	struct usbnet *dev = bus->priv;
@@ -1052,7 +1090,6 @@  static void smsc95xx_handle_link_change(struct net_device *net)
 static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf)
 {
 	struct smsc95xx_priv *pdata;
-	bool is_internal_phy;
 	char usb_path[64];
 	int ret, phy_irq;
 	u32 val;
@@ -1133,13 +1170,14 @@  static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf)
 	if (ret < 0)
 		goto free_mdio;
 
-	is_internal_phy = !(val & HW_CFG_PSEL_);
-	if (is_internal_phy)
+	pdata->is_internal_phy = !(val & HW_CFG_PSEL_);
+	if (pdata->is_internal_phy)
 		pdata->mdiobus->phy_mask = ~(1u << SMSC95XX_INTERNAL_PHY_ID);
 
 	pdata->mdiobus->priv = dev;
 	pdata->mdiobus->read = smsc95xx_mdiobus_read;
 	pdata->mdiobus->write = smsc95xx_mdiobus_write;
+	pdata->mdiobus->reset = smsc95xx_mdiobus_reset;
 	pdata->mdiobus->name = "smsc95xx-mdiobus";
 	pdata->mdiobus->parent = &dev->udev->dev;
 
@@ -1160,7 +1198,7 @@  static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf)
 	}
 
 	pdata->phydev->irq = phy_irq;
-	pdata->phydev->is_internal = is_internal_phy;
+	pdata->phydev->is_internal = pdata->is_internal_phy;
 
 	/* detect device revision as different features may be available */
 	ret = smsc95xx_read_reg(dev, ID_REV, &val);