diff --git a/drivers/pci/intr_remapping.c b/drivers/pci/intr_remapping.c
index c26633d..ef25caa 100644
--- a/drivers/pci/intr_remapping.c
+++ b/drivers/pci/intr_remapping.c
@@ -415,12 +415,27 @@
 
 	/* Set interrupt-remapping table pointer */
 	cmd = iommu->gcmd | DMA_GCMD_SIRTP;
+	iommu->gcmd |= DMA_GCMD_SIRTP;
 	writel(cmd, iommu->reg + DMAR_GCMD_REG);
 
 	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 		      readl, (sts & DMA_GSTS_IRTPS), sts);
 	spin_unlock_irqrestore(&iommu->register_lock, flags);
 
+	if (mode == 0) {
+		spin_lock_irqsave(&iommu->register_lock, flags);
+
+		/* enable comaptiblity format interrupt pass through */
+		cmd = iommu->gcmd | DMA_GCMD_CFI;
+		iommu->gcmd |= DMA_GCMD_CFI;
+		writel(cmd, iommu->reg + DMAR_GCMD_REG);
+
+		IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
+			      readl, (sts & DMA_GSTS_CFIS), sts);
+
+		spin_unlock_irqrestore(&iommu->register_lock, flags);
+	}
+
 	/*
 	 * global invalidation of interrupt entry cache before enabling
 	 * interrupt-remapping.