[PATCH 2.6.21 1/3] cxgb3 - avoid deadlock with mac watchdog

[divy@chelsio.com]

From: Divy Le Ray <divy@chelsio.com>

Fix a deadlock when the interface s configured down and 
the watchdog tack is sleeping on rtnl_lock.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
---

 drivers/net/cxgb3/cxgb3_main.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/net/cxgb3/cxgb3_main.c b/drivers/net/cxgb3/cxgb3_main.c
index 26240fd..c6ebe25 100644
--- a/drivers/net/cxgb3/cxgb3_main.c
+++ b/drivers/net/cxgb3/cxgb3_main.c
@@ -2119,7 +2119,9 @@ static void check_t3b2_mac(struct adapte
 {
 	int i;
 
-	rtnl_lock();                      /* synchronize with ifdown */
+	if (!rtnl_trylock())	/* synchronize with ifdown */
+		return;
+
 	for_each_port(adapter, i) {
 		struct net_device *dev = adapter->port[i];
 		struct port_info *p = netdev_priv(dev);