diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 98f555d..b287ca3 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2466,18 +2466,16 @@
 
 		/* allocate a protection domain if a device is added */
 		dma_domain = find_protection_domain(devid);
-		if (dma_domain)
-			goto out;
-		dma_domain = dma_ops_domain_alloc();
-		if (!dma_domain)
-			goto out;
-		dma_domain->target_dev = devid;
+		if (!dma_domain) {
+			dma_domain = dma_ops_domain_alloc();
+			if (!dma_domain)
+				goto out;
+			dma_domain->target_dev = devid;
 
-		spin_lock_irqsave(&iommu_pd_list_lock, flags);
-		list_add_tail(&dma_domain->list, &iommu_pd_list);
-		spin_unlock_irqrestore(&iommu_pd_list_lock, flags);
-
-		dev_data = get_dev_data(dev);
+			spin_lock_irqsave(&iommu_pd_list_lock, flags);
+			list_add_tail(&dma_domain->list, &iommu_pd_list);
+			spin_unlock_irqrestore(&iommu_pd_list_lock, flags);
+		}
 
 		dev->archdata.dma_ops = &amd_iommu_dma_ops;