https://bugs.freedesktop.org/show_bug.cgi?id=41265
--- Comment #35 from gyhor@gmx.de 2012-08-16 08:39:35 UTC --- Function radeon_atrm_call() would not be called, because if (!radeon_atrm_supported(rdev->pdev)) returns false.
Thats because this is returns null: (!radeon_atpx_priv.atpx_detected)