diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 9dc7facfd2e581f4b4d49b0d6d5ce0a8363f2077..3c1a29104f0e2fcbbdb5bc21bf15ae250d6a4221 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3682,13 +3682,12 @@ static int alloc_irq_index(u16 devid, int count, bool align)
 
 	/* Scan table for free entries */
 	for (index = ALIGN(table->min_index, alignment), c = 0;
-	     index < MAX_IRQS_PER_TABLE;
-	     index++) {
+	     index < MAX_IRQS_PER_TABLE;) {
 		if (!iommu->irte_ops->is_allocated(table, index)) {
 			c += 1;
 		} else {
 			c     = 0;
-			index = ALIGN(index, alignment);
+			index = ALIGN(index + 1, alignment);
 			continue;
 		}
 
@@ -3699,6 +3698,8 @@ static int alloc_irq_index(u16 devid, int count, bool align)
 			index -= count - 1;
 			goto out;
 		}
+
+		index++;
 	}
 
 	index = -ENOSPC;