[PATCH] netdev/fec: fix ifconfig eth0 down hang issue (v4)

[Bryan Wu]

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

v4:
 - don't touch suspend/resume functions in this patch
 - set fep->phy_dev = NULL in the fec_enet_mii_probe() entry

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 |   13 ++++++++++++-
 1 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/drivers/net/fec.c b/drivers/net/fec.c
index 2280373..dff9d96 100644
--- a/drivers/net/fec.c
+++ b/drivers/net/fec.c
@@ -691,6 +691,8 @@ 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]) {
@@ -929,7 +931,13 @@ 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 +950,13 @@ 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);
 
-- 
1.7.0.1