diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
index bff2420fc3e1..7c20083d4a79 100644
--- a/drivers/iommu/intel/dmar.c
+++ b/drivers/iommu/intel/dmar.c
@@ -1080,7 +1080,8 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd)
 	}
 
 	err = -EINVAL;
-	if (cap_sagaw(iommu->cap) == 0) {
+	if (!cap_sagaw(iommu->cap) &&
+	    (!ecap_smts(iommu->ecap) || ecap_slts(iommu->ecap))) {
 		pr_info("%s: No supported address widths. Not attempting DMA translation.\n",
 			iommu->name);
 		drhd->ignored = 1;