netdev/fec: fix ifconfig eth0 down hang issue

BugLink: http://bugs.launchpad.net/bugs/559065

In fec open/close function, we need to use phy_connect and phy_disconnect
operation before we start/stop phy. Otherwise it will cause system hang.

Only call fec_enet_mii_probe() in open function, because the first open
action will cause NULL pointer error.

Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 12 deletions

diff --git a/drivers/net/fec.c b/drivers/net/fec.c
index 326465ffbb23..ddf7a86cd466 100644
--- a/drivers/net/fec.c
+++ b/drivers/net/fec.c
@@ -681,6 +681,8 @@ static int fec_enet_mii_probe(struct net_device *dev)
         struct phy_device *phy_dev = NULL;
         int phy_addr;
 
+        fep->phy_dev = NULL;
+
         /* find the first phy */
         for (phy_addr = 0; phy_addr < PHY_MAX_ADDR; phy_addr++) {
                 if (fep->mii_bus->phy_map[phy_addr]) {
@@ -711,6 +713,11 @@ static int fec_enet_mii_probe(struct net_device *dev)
         fep->link = 0;
         fep->full_duplex = 0;
 
+        printk(KERN_INFO "%s: Freescale FEC PHY driver [%s] "
+                "(mii_bus:phy_addr=%s, irq=%d)\n", dev->name,
+                fep->phy_dev->drv->name, dev_name(&fep->phy_dev->dev),
+                fep->phy_dev->irq);
+
         return 0;
 }
 
@@ -756,13 +763,8 @@ static int fec_enet_mii_init(struct platform_device *pdev)
         if (mdiobus_register(fep->mii_bus))
                 goto err_out_free_mdio_irq;
 
-        if (fec_enet_mii_probe(dev) != 0)
-                goto err_out_unregister_bus;
-
         return 0;
 
-err_out_unregister_bus:
-        mdiobus_unregister(fep->mii_bus);
 err_out_free_mdio_irq:
         kfree(fep->mii_bus->irq);
 err_out_free_mdiobus:
@@ -915,7 +917,12 @@ fec_enet_open(struct net_device *dev)
         if (ret)
                 return ret;
 
-        /* schedule a link state check */
+        /* Probe and connect to PHY when open the interface */
+        ret = fec_enet_mii_probe(dev);
+        if (ret) {
+                fec_enet_free_buffers(dev);
+                return ret;
+        }
         phy_start(fep->phy_dev);
         netif_start_queue(dev);
         fep->opened = 1;
@@ -929,10 +936,12 @@ fec_enet_close(struct net_device *dev)
 
         /* Don't know what to do yet. */
         fep->opened = 0;
-        phy_stop(fep->phy_dev);
         netif_stop_queue(dev);
         fec_stop(dev);
 
+        if (fep->phy_dev)
+                phy_disconnect(fep->phy_dev);
+
         fec_enet_free_buffers(dev);
 
         return 0;
@@ -1316,11 +1325,6 @@ fec_probe(struct platform_device *pdev)
         if (ret)
                 goto failed_register;
 
-        printk(KERN_INFO "%s: Freescale FEC PHY driver [%s] "
-                "(mii_bus:phy_addr=%s, irq=%d)\n", ndev->name,
-                fep->phy_dev->drv->name, dev_name(&fep->phy_dev->dev),
-                fep->phy_dev->irq);
-
         return 0;
 
 failed_register: