phylib: Properly reinitialize PHYs after hibernation

Since hibernation assumes power loss, we should fully reinitialize
PHYs (including platform fixups), as if PHYs were just attached.

This patch factors phy_init_hw() out of phy_attach_direct(), then
converts mdio_bus to dev_pm_ops and adds an appropriate restore()
callback.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/mdio_bus.c

@@ -264,6 +264,8 @@ static int mdio_bus_match(struct device *dev, struct device_driver *drv)
 		(phydev->phy_id & phydrv->phy_id_mask));
 }
 
+#ifdef CONFIG_PM
+
 static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
 {
 	struct device_driver *drv = phydev->dev.driver;
@@ -295,10 +297,7 @@ static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
 	return true;
 }
 
-/* Suspend and resume.  Copied from platform_suspend and
- * platform_resume
- */
-static int mdio_bus_suspend(struct device * dev, pm_message_t state)
+static int mdio_bus_suspend(struct device *dev)
 {
 	struct phy_driver *phydrv = to_phy_driver(dev->driver);
 	struct phy_device *phydev = to_phy_device(dev);
@@ -318,7 +317,7 @@ static int mdio_bus_suspend(struct device * dev, pm_message_t state)
 	return phydrv->suspend(phydev);
 }
 
-static int mdio_bus_resume(struct device * dev)
+static int mdio_bus_resume(struct device *dev)
 {
 	struct phy_driver *phydrv = to_phy_driver(dev->driver);
 	struct phy_device *phydev = to_phy_device(dev);
@@ -338,11 +337,48 @@ no_resume:
 	return 0;
 }
 
+static int mdio_bus_restore(struct device *dev)
+{
+	struct phy_device *phydev = to_phy_device(dev);
+	struct net_device *netdev = phydev->attached_dev;
+	int ret;
+
+	if (!netdev)
+		return 0;
+
+	ret = phy_init_hw(phydev);
+	if (ret < 0)
+		return ret;
+
+	/* The PHY needs to renegotiate. */
+	phydev->link = 0;
+	phydev->state = PHY_UP;
+
+	phy_start_machine(phydev, NULL);
+
+	return 0;
+}
+
+static struct dev_pm_ops mdio_bus_pm_ops = {
+	.suspend = mdio_bus_suspend,
+	.resume = mdio_bus_resume,
+	.freeze = mdio_bus_suspend,
+	.thaw = mdio_bus_resume,
+	.restore = mdio_bus_restore,
+};
+
+#define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
+
+#else
+
+#define MDIO_BUS_PM_OPS NULL
+
+#endif /* CONFIG_PM */
+
 struct bus_type mdio_bus_type = {
 	.name		= "mdio_bus",
 	.match		= mdio_bus_match,
-	.suspend	= mdio_bus_suspend,
-	.resume		= mdio_bus_resume,
+	.pm		= MDIO_BUS_PM_OPS,
 };
 EXPORT_SYMBOL(mdio_bus_type);
 

drivers/net/phy/phy_device.c

@@ -378,6 +378,20 @@ void phy_disconnect(struct phy_device *phydev)
 }
 EXPORT_SYMBOL(phy_disconnect);
 
+int phy_init_hw(struct phy_device *phydev)
+{
+	int ret;
+
+	if (!phydev->drv || !phydev->drv->config_init)
+		return 0;
+
+	ret = phy_scan_fixups(phydev);
+	if (ret < 0)
+		return ret;
+
+	return phydev->drv->config_init(phydev);
+}
+
 /**
  * phy_attach_direct - attach a network device to a given PHY device pointer
  * @dev: network device to attach
@@ -425,21 +439,7 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
 	/* Do initial configuration here, now that
 	 * we have certain key parameters
 	 * (dev_flags and interface) */
-	if (phydev->drv->config_init) {
-		int err;
-
-		err = phy_scan_fixups(phydev);
-
-		if (err < 0)
-			return err;
-
-		err = phydev->drv->config_init(phydev);
-
-		if (err < 0)
-			return err;
-	}
-
-	return 0;
+	return phy_init_hw(phydev);
 }
 EXPORT_SYMBOL(phy_attach_direct);
 

include/linux/phy.h

@@ -447,6 +447,7 @@ struct phy_device* get_phy_device(struct mii_bus *bus, int addr);
 int phy_device_register(struct phy_device *phy);
 int phy_clear_interrupt(struct phy_device *phydev);
 int phy_config_interrupt(struct phy_device *phydev, u32 interrupts);
+int phy_init_hw(struct phy_device *phydev);
 int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
 		u32 flags, phy_interface_t interface);
 struct phy_device * phy_attach(struct net_device *dev,