[PATCH v8 13/13] iommu/amd: Disable iommu only if amd_iommu=off is specified

[Baoquan He]

From: root <root@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>

It's ok to disable iommu in normal kernel. While there's no need
to disable it in kdump kernel after the on-flight dma issue has
heen fixed.

Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
---
 drivers/iommu/amd_iommu_init.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 8b4bac978062..880f693c809b 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -2494,7 +2494,8 @@ static int __init early_amd_iommu_init(void)
 		goto out;
 
 	/* Disable any previously enabled IOMMUs */
-	disable_iommus();
+	if (amd_iommu_disabled)
+		disable_iommus();
 
 	if (amd_iommu_irq_remap)
 		amd_iommu_irq_remap = check_ioapic_information();
-- 
2.5.5