[PATCH 3.16 137/217] rapidio/rionet: fix deadlock on SMP

[Ben Hutchings]

3.16.35-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Aurelien Jacquiot <a-jacquiot@xxxxxx>

commit 36915976eca58f2eefa040ba8f9939672564df61 upstream.

Fix deadlocking during concurrent receive and transmit operations on SMP
platforms caused by the use of incorrect lock: on transmit 'tx_lock'
spinlock should be used instead of 'lock' which is used for receive
operation.

This fix is applicable to kernel versions starting from v2.15.

Signed-off-by: Aurelien Jacquiot <a-jacquiot@xxxxxx>
Signed-off-by: Alexandre Bounine <alexandre.bounine@xxxxxxx>
Cc: Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx>
Cc: Andre van Herk <andre.van.herk@xxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/net/rionet.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/rionet.c
+++ b/drivers/net/rionet.c
@@ -280,7 +280,7 @@ static void rionet_outb_msg_event(struct
 	struct net_device *ndev = dev_id;
 	struct rionet_private *rnet = netdev_priv(ndev);
 
-	spin_lock(&rnet->lock);
+	spin_lock(&rnet->tx_lock);
 
 	if (netif_msg_intr(rnet))
 		printk(KERN_INFO
@@ -299,7 +299,7 @@ static void rionet_outb_msg_event(struct
 	if (rnet->tx_cnt < RIONET_TX_RING_SIZE)
 		netif_wake_queue(ndev);
 
-	spin_unlock(&rnet->lock);
+	spin_unlock(&rnet->tx_lock);
 }
 
 static int rionet_open(struct net_device *ndev)