diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index e531a2b07207..142650e82979 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -698,13 +698,13 @@ int __init dmar_dev_scope_init(void)
 	if (dmar_dev_scope_status != 1)
 		return dmar_dev_scope_status;
 
-	dmar_acpi_dev_scope_init();
-
 	if (list_empty(&dmar_drhd_units)) {
 		dmar_dev_scope_status = -ENODEV;
 	} else {
 		dmar_dev_scope_status = 0;
 
+		dmar_acpi_dev_scope_init();
+
 		for_each_pci_dev(dev) {
 			if (dev->is_virtfn)
 				continue;