[PATCH] netdev/fec: fix ifconfig eth0 down hang issue (v3)

[Bryan Wu]

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

v3:
if fec_enet_mii_probe() fails, we should exit the open and resume functions
properly and give up further operations without a proper PHY connected.

v2:
Check fec_enet_mii_probe() return value directly, instead of fep->phy_dev

v1:
In ethernet connection open/close function, we need to use phy_connect
and phy_disconnect operation before we start/stop phy. Otherwise it will
cause system hang. Also suspend/resume needs the same fix.

Signed-off-by: Bryan Wu <bryan.wu at canonical.com>
---
 drivers/net/fec.c |   21 ++++++++++++++++++++-
 1 files changed, 20 insertions(+), 1 deletions(-)

diff --git a/drivers/net/fec.c b/drivers/net/fec.c
index 2280373..b14e4d5 100644
--- a/drivers/net/fec.c
+++ b/drivers/net/fec.c
@@ -929,7 +929,13 @@ fec_enet_open(struct net_device *dev)
 		return ret;
 
 	/* schedule a link state check */
+	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;
 	return 0;
@@ -942,10 +948,13 @@ 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);
 	clk_disable(fep->clk);
 
@@ -1396,6 +1405,8 @@ fec_suspend(struct platform_device *dev, pm_message_t state)
 		fep = netdev_priv(ndev);
 		if (netif_running(ndev)) {
 			netif_device_detach(ndev);
+			if (fep->phy_dev)
+				phy_disconnect(fep->phy_dev);
 			fec_stop(ndev);
 			clk_disable(fep->clk);
 		}
@@ -1409,12 +1420,20 @@ fec_resume(struct platform_device *dev)
 {
 	struct net_device *ndev = platform_get_drvdata(dev);
 	struct fec_enet_private *fep;
+	int ret;
 
 	if (ndev) {
 		fep = netdev_priv(ndev);
 		if (netif_running(ndev)) {
 			clk_enable(fep->clk);
 			fec_restart(ndev, 1);
+			ret = fec_enet_mii_probe(ndev);
+			if (!ret) {
+				fec_stop(ndev);
+				clk_disable(fep->clk);
+				return ret;
+			}
+			phy_start(fep->phy_dev);
 			netif_device_attach(ndev);
 		}
 	}
-- 
1.7.0.1