With the debug patch applied to your 3.14-wip branch (based on 3.13-rc4), the
following is printed by the Linux kernel.

    [   12.005985] [drm:radeon_fixup_lvds_native_mode], Native mode:
1920x1080-138780

The clock looks strange to me, as I would have expected the refresh rate. But I
guess I just do not know what it is supposed to do.

(I had to do eight xrandr off/auto cycles to get the display to work.)