Use the helpers introduced by the commit below to properly initialize
the duplicated states.
commit 
f5e7840b0c4368f8cdbb055188c2a0eef50c3052
Author: Thierry Reding <treding@nvidia.com>
Date:   Wed Jan 28 14:54:32 2015 +0100
    drm/atomic: Add helpers for state-subclassing drivers
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
                crtc_state = kmemdup(intel_crtc->config,
                                     sizeof(*intel_crtc->config), GFP_KERNEL);
 
-       if (crtc_state)
-               crtc_state->base.crtc = crtc;
+       if (!crtc_state)
+               return NULL;
+
+       __drm_atomic_helper_crtc_duplicate_state(crtc, &crtc_state->base);
+
+       crtc_state->base.crtc = crtc;
 
        return &crtc_state->base;
 }
 
                return NULL;
 
        state = &intel_state->base;
-       if (state->fb)
-               drm_framebuffer_reference(state->fb);
+
+       __drm_atomic_helper_plane_duplicate_state(plane, state);
 
        return state;
 }