return 0;
 }
 
-int dispc_ovl_setup(enum omap_plane plane, struct omap_overlay_info *oi,
+int dispc_ovl_setup(enum omap_plane plane, const struct omap_overlay_info *oi,
                bool replication, const struct omap_video_timings *mgr_timings)
 {
        struct omap_overlay *ovl = omap_dss_get_overlay(plane);
        enum omap_channel channel;
        int x_predecim = 1, y_predecim = 1;
        bool ilace = mgr_timings->interlace;
+       u16 pos_y = oi->pos_y;
 
        channel = dispc_ovl_get_channel_out(plane);
 
        if (ilace) {
                if (fieldmode)
                        in_height /= 2;
-               oi->pos_y /= 2;
+               pos_y /= 2;
                out_height /= 2;
 
                DSSDBG("adjusting for ilace: height %d, pos_y %d, "
                                "out_height %d\n",
-                               in_height, oi->pos_y, out_height);
+                               in_height, pos_y, out_height);
        }
 
        if (!dss_feat_color_mode_supported(plane, oi->color_mode))
        DSSDBG("%d,%d %dx%d -> %dx%d\n", oi->pos_x, oi->pos_y, in_width,
                        in_height, out_width, out_height);
 
-       dispc_ovl_set_pos(plane, oi->pos_x, oi->pos_y);
+       dispc_ovl_set_pos(plane, oi->pos_x, pos_y);
 
        dispc_ovl_set_pic_size(plane, in_width, in_height);
 
 
 void dispc_ovl_compute_fifo_thresholds(enum omap_plane plane,
                u32 *fifo_low, u32 *fifo_high, bool use_fifomerge,
                bool manual_update);
-int dispc_ovl_setup(enum omap_plane plane, struct omap_overlay_info *oi,
+int dispc_ovl_setup(enum omap_plane plane, const struct omap_overlay_info *oi,
                bool replication, const struct omap_video_timings *mgr_timings);
 int dispc_ovl_enable(enum omap_plane plane, bool enable);
 void dispc_ovl_set_channel_out(enum omap_plane plane,