.set_crc_source = rcar_du_crtc_set_crc_source,
        .verify_crc_source = rcar_du_crtc_verify_crc_source,
        .get_crc_sources = rcar_du_crtc_get_crc_sources,
+       .gamma_set = drm_atomic_helper_legacy_gamma_set,
 };
 
 /* -----------------------------------------------------------------------------
        if (rcdu->cmms[swindex]) {
                rcrtc->cmm = rcdu->cmms[swindex];
                rgrp->cmms_mask |= BIT(hwindex % 2);
+
+               drm_mode_crtc_set_gamma_size(crtc, CM2_LUT_SIZE);
+               drm_crtc_enable_color_mgmt(crtc, 0, false, CM2_LUT_SIZE);
        }
 
        drm_crtc_helper_add(crtc, &crtc_helper_funcs);