[3.13.y-ckt stable] Patch "rapidio/rionet: fix deadlock on SMP" has been added to the 3.13.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    rapidio/rionet: fix deadlock on SMP

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt38.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 45066ff55c4065d6bf484cb6f19f3ba6114b5535 Mon Sep 17 00:00:00 2001
From: Aurelien Jacquiot <a-jacquiot at ti.com>
Date: Tue, 22 Mar 2016 14:25:42 -0700
Subject: rapidio/rionet: fix deadlock on SMP

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 at ti.com>
Signed-off-by: Alexandre Bounine <alexandre.bounine at idt.com>
Cc: Matt Porter <mporter at kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk at prodrive-technologies.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 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 6d1f6ed..d93bac1 100644
--- a/drivers/net/rionet.c
+++ b/drivers/net/rionet.c
@@ -280,7 +280,7 @@ 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))
 		printk(KERN_INFO
@@ -299,7 +299,7 @@ static void rionet_outb_msg_event(struct rio_mport *mport, void *dev_id, int mbo
 	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)
--
2.7.4