diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 8c00a7a06c32dc71e5c625084303b8f5b2424397..c9ceea46711ef0246b0201552838f4f5ca50718a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1177,8 +1177,9 @@ int amdgpu_ttm_tt_get_userptr(const struct ttm_buffer_object *tbo,
  * @addr:  The address in the current tasks VM space to use
  * @flags: Requirements of userptr object.
  *
- * Called by amdgpu_gem_userptr_ioctl() to bind userptr pages
- * to current task
+ * Called by amdgpu_gem_userptr_ioctl() and kfd_ioctl_alloc_memory_of_gpu() to
+ * bind userptr pages to current task and by kfd_ioctl_acquire_vm() to
+ * initialize GPU VM for a KFD process.
  */
 int amdgpu_ttm_tt_set_userptr(struct ttm_buffer_object *bo,
 			      uint64_t addr, uint32_t flags)