diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index 5d52020deca1..074db7a92809 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -264,7 +264,6 @@ static int rockchip_drm_gem_object_mmap(struct drm_gem_object *obj,
 	 * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap().
 	 */
 	vma->vm_flags &= ~VM_PFNMAP;
-	vma->vm_pgoff = 0;
 
 	if (rk_obj->pages)
 		ret = rockchip_drm_gem_object_mmap_iommu(obj, vma);
@@ -299,6 +298,12 @@ int rockchip_gem_mmap(struct file *filp, struct vm_area_struct *vma)
 	if (ret)
 		return ret;
 
+	/*
+	 * Set vm_pgoff (used as a fake buffer offset by DRM) to 0 and map the
+	 * whole buffer from the start.
+	 */
+	vma->vm_pgoff = 0;
+
 	obj = vma->vm_private_data;
 
 	return rockchip_drm_gem_object_mmap(obj, vma);