ocelot: Clean up stats update deferred work

This is preventive cleanup that may save troubles later.
No need to cancel repeateadly queued work if code is properly
refactored.
Don't let the ethtool -s process interfere with the stat workqueue
scheduling.
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mscc/ocelot.c

@@ -959,10 +959,8 @@ static void ocelot_get_strings(struct net_device *netdev, u32 sset, u8 *data)
 		       ETH_GSTRING_LEN);
 }
 
-static void ocelot_check_stats(struct work_struct *work)
+static void ocelot_update_stats(struct ocelot *ocelot)
 {
-	struct delayed_work *del_work = to_delayed_work(work);
-	struct ocelot *ocelot = container_of(del_work, struct ocelot, stats_work);
 	int i, j;
 
 	mutex_lock(&ocelot->stats_lock);
@@ -986,11 +984,19 @@ static void ocelot_check_stats(struct work_struct *work)
 		}
 	}
 
-	cancel_delayed_work(&ocelot->stats_work);
+	mutex_unlock(&ocelot->stats_lock);
+}
+
+static void ocelot_check_stats_work(struct work_struct *work)
+{
+	struct delayed_work *del_work = to_delayed_work(work);
+	struct ocelot *ocelot = container_of(del_work, struct ocelot,
+					     stats_work);
+
+	ocelot_update_stats(ocelot);
+
 	queue_delayed_work(ocelot->stats_queue, &ocelot->stats_work,
 			   OCELOT_STATS_CHECK_DELAY);
-
-	mutex_unlock(&ocelot->stats_lock);
 }
 
 static void ocelot_get_ethtool_stats(struct net_device *dev,
@@ -1001,7 +1007,7 @@ static void ocelot_get_ethtool_stats(struct net_device *dev,
 	int i;
 
 	/* check and update now */
-	ocelot_check_stats(&ocelot->stats_work.work);
+	ocelot_update_stats(ocelot);
 
 	/* Copy all counters */
 	for (i = 0; i < ocelot->num_stats; i++)
@@ -1809,7 +1815,7 @@ int ocelot_init(struct ocelot *ocelot)
 				 ANA_CPUQ_8021_CFG_CPUQ_BPDU_VAL(6),
 				 ANA_CPUQ_8021_CFG, i);
 
-	INIT_DELAYED_WORK(&ocelot->stats_work, ocelot_check_stats);
+	INIT_DELAYED_WORK(&ocelot->stats_work, ocelot_check_stats_work);
 	queue_delayed_work(ocelot->stats_queue, &ocelot->stats_work,
 			   OCELOT_STATS_CHECK_DELAY);
 	return 0;