*** drivers/gpu/drm/udl/udl_drv.c.orig	2017-05-14 18:28:55.765966608 +0200
--- drivers/gpu/drm/udl/udl_drv.c	2017-05-14 18:30:46.872445409 +0200
***************
*** 53,58 ****
--- 53,59 ----
  	.load = udl_driver_load,
  	.unload = udl_driver_unload,
  	.set_busid = udl_driver_set_busid,
+ 	.get_vblank_counter = drm_vblank_count,
  
  	/* gem hooks */
  	.gem_free_object = udl_gem_free_object,