diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 142650e82979..f445c10df8df 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -662,10 +662,9 @@ static int __init dmar_acpi_dev_scope_init(void)
 	if (dmar_tbl == NULL)
 		return -ENODEV;
 
-	andd = (void *)dmar_tbl + sizeof(struct acpi_table_dmar);
-
-	while (((unsigned long)andd) <
-	       ((unsigned long)dmar_tbl) + dmar_tbl->length) {
+	for (andd = (void *)dmar_tbl + sizeof(struct acpi_table_dmar);
+	     ((unsigned long)andd) < ((unsigned long)dmar_tbl) + dmar_tbl->length;
+	     andd = ((void *)andd) + andd->header.length) {
 		if (andd->header.type == ACPI_DMAR_TYPE_ANDD) {
 			acpi_handle h;
 			struct acpi_device *adev;
@@ -685,7 +684,6 @@ static int __init dmar_acpi_dev_scope_init(void)
 			}
 			dmar_acpi_insert_dev_scope(andd->device_number, adev);
 		}
-		andd = ((void *)andd) + andd->header.length;
 	}
 	return 0;
 }