i40iw: Receive notification events correctly

shirazsaleem · dledford · commit b71121b4b70a · 2016-08-26T09:59:13.000-04:00
Device notifications are not received after the first interface is closed; since there is an unregister for notifications on every interface close. Correct this by unregistering for device notifications only when the last interface is closed. Also, make all operations on the i40iw_notifiers_registered atomic as it can be read/modified concurrently. Fixes: 8e06af7 ("i40iw: add main, hdr, status") Signed-off-by: Mustafa Ismail <mustafa.ismail@intel.com> Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/hw/i40iw/i40iw_main.c b/drivers/infiniband/hw/i40iw/i40iw_main.c
@@ -100,7 +100,7 @@ static struct notifier_block i40iw_net_notifier = {
 	.notifier_call = i40iw_net_event
 };
 
-static int i40iw_notifiers_registered;
+static atomic_t i40iw_notifiers_registered;
 
 /**
  * i40iw_find_i40e_handler - find a handler given a client info
@@ -1342,12 +1342,11 @@ static enum i40iw_status_code i40iw_initialize_dev(struct i40iw_device *iwdev,
  */
 static void i40iw_register_notifiers(void)
 {
-	if (!i40iw_notifiers_registered) {
+	if (atomic_inc_return(&i40iw_notifiers_registered) == 1) {
 		register_inetaddr_notifier(&i40iw_inetaddr_notifier);
 		register_inet6addr_notifier(&i40iw_inetaddr6_notifier);
 		register_netevent_notifier(&i40iw_net_notifier);
 	}
-	i40iw_notifiers_registered++;
 }
 
 /**
@@ -1429,8 +1428,7 @@ static void i40iw_deinit_device(struct i40iw_device *iwdev, bool reset, bool del
 			i40iw_del_macip_entry(iwdev, (u8)iwdev->mac_ip_table_idx);
 		/* fallthrough */
 	case INET_NOTIFIER:
-		if (i40iw_notifiers_registered > 0) {
-			i40iw_notifiers_registered--;
+		if (!atomic_dec_return(&i40iw_notifiers_registered)) {
 			unregister_netevent_notifier(&i40iw_net_notifier);
 			unregister_inetaddr_notifier(&i40iw_inetaddr_notifier);
 			unregister_inet6addr_notifier(&i40iw_inetaddr6_notifier);
