diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
index cbd133eb25aa..4c58306c606f 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
@@ -162,8 +162,10 @@ static int init_loader_memory(struct drm_device *drm_dev)
 
 		logo->dma_addr = logo->mm.start;
 
-		if (iommu_map_sg(private->domain, logo->dma_addr, sgt->sgl,
-				 sgt->nents, prot) < size) {
+		logo->iommu_map_size = iommu_map_sg(private->domain,
+						    logo->dma_addr, sgt->sgl,
+						    sgt->nents, prot);
+		if (logo->iommu_map_size < size) {
 			DRM_ERROR("failed to map buffer");
 			ret = -ENOMEM;
 			goto err_remove_node;
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.h b/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
index 8ddc21eadc39..8a8d67381e74 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
@@ -102,6 +102,7 @@ struct rockchip_logo {
 	dma_addr_t dma_addr;
 	phys_addr_t start;
 	phys_addr_t size;
+	size_t iommu_map_size;
 	int count;
 };
 
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
index 7bb9e787bf41..9b8d15b1e267 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
@@ -67,7 +67,7 @@ static void rockchip_drm_fb_destroy(struct drm_framebuffer *fb)
 
 			if (private && private->domain) {
 				iommu_unmap(private->domain, logo->dma_addr,
-					    logo->size);
+					    logo->iommu_map_size);
 				drm_mm_remove_node(&logo->mm);
 			} else {
 				dma_unmap_sg(fb->dev->dev, logo->sgt->sgl,