1 files changed, 64 insertions, 8 deletions

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index bd4e8d72dc08..e17b70291bbc 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/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;
@@ -295,34 +297,88 @@ 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);
 
+        /*
+         * We must stop the state machine manually, otherwise it stops out of
+         * control, possibly with the phydev->lock held. Upon resume, netdev
+         * may call phy routines that try to grab the same lock, and that may
+         * lead to a deadlock.
+         */
+        if (phydev->attached_dev)
+                phy_stop_machine(phydev);
+
         if (!mdio_bus_phy_may_suspend(phydev))
                 return 0;
+
         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);
+        int ret;
 
         if (!mdio_bus_phy_may_suspend(phydev))
+                goto no_resume;
+
+        ret = phydrv->resume(phydev);
+        if (ret < 0)
+                return ret;
+
+no_resume:
+        if (phydev->attached_dev)
+                phy_start_machine(phydev, NULL);
+
+        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;
-        return phydrv->resume(phydev);
+
+        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);