[PATCH] netpoll: WARN_ONCE for start_xmit returns with interrupts enabled

[DDD <Dongdong.deng@windriver.com>]

The NETPOLL API requires that interrupts remain disabled in
netpoll_send_skb().

Add a WARN_ONCE when ndo_start_xmit returns with interrupts enabled
in netpoll_send_skb().

Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
---
 net/core/netpoll.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index df30feb..d38103f 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -319,6 +319,12 @@ static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
 
 			udelay(USEC_PER_POLL);
 		}
+
+		WARN_ONCE(!irqs_disabled(),
+			KERN_WARNING "netpoll_send_skb(): [net driver %s]"
+			"ndo_start_xmit() shouldn't return with interrupts"
+			"enabled!", dev->name);
+
 		local_irq_restore(flags);
 	}
 
-- 
1.6.0.4