diff --git a/drivers/gpu/drm/exynos/exynos_drm_iommu.c b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
index b32b291f88ff..323601a52a25 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_iommu.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
@@ -100,6 +100,9 @@ int drm_iommu_attach_device(struct drm_device *drm_dev,
 
 	dma_set_max_seg_size(subdrv_dev, 0xffffffffu);
 
+	if (subdrv_dev->archdata.mapping)
+		arm_iommu_detach_device(subdrv_dev);
+
 	ret = arm_iommu_attach_device(subdrv_dev, dev->archdata.mapping);
 	if (ret < 0) {
 		DRM_DEBUG_KMS("failed iommu attach.\n");