PM: runtime: Fix ordering in pm_runtime_get_suppliers()

stable inclusion
from linux-4.19.185
commit 5f40a359356b05ec28a802d6c60babdee3f90e44

--------------------------------

commit c0c33442 upstream.

rpm_active indicates how many times the supplier usage_count has been
incremented. Consequently it must be updated after pm_runtime_get_sync() of
the supplier, not before.

Fixes: 4c06c4e6 ("driver core: Fix possible supplier PM-usage counter imbalance")
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: 5.1+ <stable@vger.kernel.org> # 5.1+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/base/power/runtime.c

@@ -1572,8 +1572,8 @@ void pm_runtime_get_suppliers(struct device *dev)
 	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
 		if (link->flags & DL_FLAG_PM_RUNTIME) {
 			link->supplier_preactivated = true;
-			refcount_inc(&link->rpm_active);
 			pm_runtime_get_sync(link->supplier);
+			refcount_inc(&link->rpm_active);
 		}
 
 	device_links_read_unlock(idx);