diff --git a/drivers/md/md.c b/drivers/md/md.c
index 541151bcfe81..0fde115e921f 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8625,50 +8625,55 @@ void md_cluster_stop(struct mddev *mddev)
 	put_cluster_ops(mddev);
 }
 
-static int is_mddev_idle(struct mddev *mddev, int init)
+static bool is_rdev_holder_idle(struct md_rdev *rdev, bool init)
 {
+	unsigned long last_events = rdev->last_events;
+
+	if (!bdev_is_partition(rdev->bdev))
+		return true;
+
+	/*
+	 * If rdev is partition, and user doesn't issue IO to the array, the
+	 * array is still not idle if user issues IO to other partitions.
+	 */
+	rdev->last_events = part_stat_read_accum(rdev->bdev->bd_disk->part0,
+						 sectors) -
+			    part_stat_read_accum(rdev->bdev, sectors);
+
+	return init || rdev->last_events <= last_events;
+}
+
+/*
+ * mddev is idle if following conditions are matched since last check:
+ * 1) mddev doesn't have normal IO completed;
+ * 2) mddev doesn't have inflight normal IO;
+ * 3) if any member disk is partition, and other partitions don't have IO
+ *    completed;
+ *
+ * Noted this checking rely on IO accounting is enabled.
+ */
+static bool is_mddev_idle(struct mddev *mddev, int init)
+{
+	unsigned long last_events = mddev->normal_io_events;
+	struct gendisk *disk;
 	struct md_rdev *rdev;
-	int idle;
-	int curr_events;
+	bool idle = true;
+
+	disk = mddev_is_dm(mddev) ? mddev->dm_gendisk : mddev->gendisk;
+	if (!disk)
+		return true;
+
+	mddev->normal_io_events = part_stat_read_accum(disk->part0, sectors);
+	if (!init && (mddev->normal_io_events > last_events ||
+		      bdev_count_inflight(disk->part0)))
+		idle = false;
 
-	idle = 1;
 	rcu_read_lock();
-	rdev_for_each_rcu(rdev, mddev) {
-		struct gendisk *disk = rdev->bdev->bd_disk;
-
-		if (!init && !blk_queue_io_stat(disk->queue))
-			continue;
-
-		curr_events = (int)part_stat_read_accum(disk->part0, sectors) -
-			      atomic_read(&disk->sync_io);
-		/* sync IO will cause sync_io to increase before the disk_stats
-		 * as sync_io is counted when a request starts, and
-		 * disk_stats is counted when it completes.
-		 * So resync activity will cause curr_events to be smaller than
-		 * when there was no such activity.
-		 * non-sync IO will cause disk_stat to increase without
-		 * increasing sync_io so curr_events will (eventually)
-		 * be larger than it was before.  Once it becomes
-		 * substantially larger, the test below will cause
-		 * the array to appear non-idle, and resync will slow
-		 * down.
-		 * If there is a lot of outstanding resync activity when
-		 * we set last_event to curr_events, then all that activity
-		 * completing might cause the array to appear non-idle
-		 * and resync will be slowed down even though there might
-		 * not have been non-resync activity.  This will only
-		 * happen once though.  'last_events' will soon reflect
-		 * the state where there is little or no outstanding
-		 * resync requests, and further resync activity will
-		 * always make curr_events less than last_events.
-		 *
-		 */
-		if (init || curr_events - rdev->last_events > 64) {
-			rdev->last_events = curr_events;
-			idle = 0;
-		}
-	}
+	rdev_for_each_rcu(rdev, mddev)
+		if (!is_rdev_holder_idle(rdev, init))
+			idle = false;
 	rcu_read_unlock();
+
 	return idle;
 }
 
diff --git a/drivers/md/md.h b/drivers/md/md.h
index b57842188f18..1982f1f18627 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -132,7 +132,7 @@ struct md_rdev {
 
 	sector_t sectors;		/* Device size (in 512bytes sectors) */
 	struct mddev *mddev;		/* RAID array if running */
-	int last_events;		/* IO event timestamp */
+	unsigned long last_events;	/* IO event timestamp */
 
 	/*
 	 * If meta_bdev is non-NULL, it means that a separate device is
@@ -520,6 +520,7 @@ struct mddev {
 							 * adding a spare
 							 */
 
+	unsigned long			normal_io_events; /* IO event timestamp */
 	atomic_t			recovery_active; /* blocks scheduled, but not written */
 	wait_queue_head_t		recovery_wait;
 	sector_t			recovery_cp;