bnx2x: SMP-safe inter_sem

Signed-off-by: Vlad Zolotarov <vladz@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/net/bnx2x_main.c b/drivers/net/bnx2x_main.c
index f20df6d7dcb5..18c380330bed 100644
--- a/drivers/net/bnx2x_main.c
+++ b/drivers/net/bnx2x_main.c
@@ -706,6 +706,8 @@ static void bnx2x_int_disable_sync(struct bnx2x *bp, int disable_hw)
 
         /* disable interrupt handling */
         atomic_inc(&bp->intr_sem);
+        smp_wmb(); /* Ensure that bp->intr_sem update is SMP-safe */
+
         if (disable_hw)
                 /* prevent the HW from sending interrupts */
                 bnx2x_int_disable(bp);
@@ -6642,7 +6644,12 @@ static void bnx2x_napi_disable(struct bnx2x *bp)
 
 static void bnx2x_netif_start(struct bnx2x *bp)
 {
-        if (atomic_dec_and_test(&bp->intr_sem)) {
+        int intr_sem;
+
+        intr_sem = atomic_dec_and_test(&bp->intr_sem);
+        smp_wmb(); /* Ensure that bp->intr_sem update is SMP-safe */
+
+        if (intr_sem) {
                 if (netif_running(bp->dev)) {
                         bnx2x_napi_enable(bp);
                         bnx2x_int_enable(bp);
@@ -8229,6 +8236,7 @@ static int __devinit bnx2x_init_bp(struct bnx2x *bp)
 
         /* Disable interrupt handling until HW is initialized */
         atomic_set(&bp->intr_sem, 1);
+        smp_wmb(); /* Ensure that bp->intr_sem update is SMP-safe */
 
         mutex_init(&bp->port.phy_mutex);