drivers/gpu/drm/radeon/Kconfig

   1 config DRM_RADEON_UMS
   2         bool "Enable userspace modesetting on radeon (DEPRECATED)"
   3         depends on DRM_RADEON
   4         help
   5           Choose this option if you still need userspace modesetting.
   6
   7           Userspace modesetting is deprecated for quite some time now, so
   8           enable this only if you have ancient versions of the DDX drivers.