[PATCH 3.10 040/143] rapidio/rionet: fix deadlock on SMP

From: Willy Tarreau
Date: Sun Jun 05 2016 - 06:56:08 EST

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

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>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Willy Tarreau <w@xxxxxx>
drivers/net/rionet.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/rionet.c b/drivers/net/rionet.c
index f433b59..00a8128 100644
--- a/drivers/net/rionet.c
+++ b/drivers/net/rionet.c
@@ -269,7 +269,7 @@ static void rionet_outb_msg_event(struct rio_mport *mport, void *dev_id, int mbo
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))
@@ -288,7 +288,7 @@ static void rionet_outb_msg_event(struct rio_mport *mport, void *dev_id, int mbo
if (rnet->tx_cnt < RIONET_TX_RING_SIZE)

- spin_unlock(&rnet->lock);
+ spin_unlock(&rnet->tx_lock);

static int rionet_open(struct net_device *ndev)