drivers/gpu/drm/radeon/Kconfig

   1 config DRM_RADEON_USERPTR
   2         bool "Always enable userptr support"
   3         depends on DRM_RADEON
   4         select MMU_NOTIFIER
   5         help
   6           This option selects CONFIG_MMU_NOTIFIER if it isn't already
   7           selected to enabled full userptr support.