}
 
 static enum intel_output_format
-intel_hdmi_output_format(struct intel_connector *connector,
+intel_hdmi_output_format(const struct intel_crtc_state *crtc_state,
+                        struct intel_connector *connector,
                         bool ycbcr_420_output)
 {
+       if (!crtc_state->has_hdmi_sink)
+               return INTEL_OUTPUT_FORMAT_RGB;
+
        if (connector->base.ycbcr_420_allowed && ycbcr_420_output)
                return INTEL_OUTPUT_FORMAT_YCBCR420;
        else
        bool ycbcr_420_only = drm_mode_is_420_only(info, adjusted_mode);
        int ret;
 
-       crtc_state->output_format = intel_hdmi_output_format(connector, ycbcr_420_only);
+       crtc_state->output_format =
+               intel_hdmi_output_format(crtc_state, connector, ycbcr_420_only);
 
        if (ycbcr_420_only && !intel_hdmi_is_ycbcr420(crtc_state)) {
                drm_dbg_kms(&i915->drm,
                    !drm_mode_is_420_also(info, adjusted_mode))
                        return ret;
 
-               crtc_state->output_format = intel_hdmi_output_format(connector, true);
+               crtc_state->output_format = intel_hdmi_output_format(crtc_state, connector, true);
                ret = intel_hdmi_compute_clock(encoder, crtc_state, respect_downstream_limits);
        }