[Patch v1 15/17] iommu/irq_remapping: Refine function irq_remapping_prepare() for maintenance

[Jiang Liu <jiang.liu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

Assign intel_irq_remap_ops to remap_ops only if
intel_irq_remap_ops.prepare() succeeds.

Signed-off-by: Jiang Liu <jiang.liu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 drivers/iommu/irq_remapping.c |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c
index eb944ed3a463..a0b26ca853ae 100644
--- a/drivers/iommu/irq_remapping.c
+++ b/drivers/iommu/irq_remapping.c
@@ -204,15 +204,15 @@ int __init irq_remapping_prepare(void)
 	if (disable_irq_remap)
 		return -ENOSYS;
 
-	remap_ops = &intel_irq_remap_ops;
-
-#ifdef CONFIG_AMD_IOMMU
-	if (amd_iommu_irq_ops.prepare() == 0) {
+	if (intel_irq_remap_ops.prepare() == 0)
+		remap_ops = &intel_irq_remap_ops;
+	else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
+		 amd_iommu_irq_ops.prepare() == 0)
 		remap_ops = &amd_iommu_irq_ops;
-		return 0;
-	}
-#endif
-	return remap_ops->prepare();
+	else
+		return -ENOSYS;
+
+	return 0;
 }
 
 int __init irq_remapping_enable(void)
-- 
1.7.10.4