drm/i915/sdvo: Only enable HDMI encodings only if the commandset is supported

As we conflated intel_sdvo->is_hdmi with both having HDMI support on the
ADD along with having HDMI support on the monitor, we would attempt to
use HDMI encodings even if the interface did not support those commands.

Reported-by: Simon Farnsworth <simon.farnsworth@onelan.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Simon Farnsworth <simon.farnsworth@onelan.co.uk>
Reviewed-by: Simon Farnsworth <simon.farnsworth@onelan.co.uk>

drivers/gpu/drm/i915/intel_sdvo.c

@@ -107,7 +107,8 @@ struct intel_sdvo {
 	 * This is set if we treat the device as HDMI, instead of DVI.
 	 */
 	bool is_hdmi;
-	bool has_audio;
+	bool has_hdmi_monitor;
+	bool has_hdmi_audio;
 
 	/**
 	 * This is set if we detect output of sdvo device as LVDS and
@@ -1023,7 +1024,7 @@ static void intel_sdvo_mode_set(struct drm_encoder *encoder,
 	if (!intel_sdvo_set_target_input(intel_sdvo))
 		return;
 
-	if (intel_sdvo->is_hdmi &&
+	if (intel_sdvo->has_hdmi_monitor &&
 	    !intel_sdvo_set_avi_infoframe(intel_sdvo))
 		return;
 
@@ -1063,7 +1064,7 @@ static void intel_sdvo_mode_set(struct drm_encoder *encoder,
 	}
 	if (intel_crtc->pipe == 1)
 		sdvox |= SDVO_PIPE_B_SELECT;
-	if (intel_sdvo->has_audio)
+	if (intel_sdvo->has_hdmi_audio)
 		sdvox |= SDVO_AUDIO_ENABLE;
 
 	if (INTEL_INFO(dev)->gen >= 4) {
@@ -1388,8 +1389,10 @@ intel_sdvo_hdmi_sink_detect(struct drm_connector *connector)
 		/* DDC bus is shared, match EDID to connector type */
 		if (edid->input & DRM_EDID_INPUT_DIGITAL) {
 			status = connector_status_connected;
-			intel_sdvo->is_hdmi = drm_detect_hdmi_monitor(edid);
-			intel_sdvo->has_audio = drm_detect_monitor_audio(edid);
+			if (intel_sdvo->is_hdmi) {
+				intel_sdvo->has_hdmi_monitor = drm_detect_hdmi_monitor(edid);
+				intel_sdvo->has_hdmi_audio = drm_detect_monitor_audio(edid);
+			}
 		}
 		connector->display_info.raw_edid = NULL;
 		kfree(edid);
@@ -1398,7 +1401,7 @@ intel_sdvo_hdmi_sink_detect(struct drm_connector *connector)
 	if (status == connector_status_connected) {
 		struct intel_sdvo_connector *intel_sdvo_connector = to_intel_sdvo_connector(connector);
 		if (intel_sdvo_connector->force_audio)
-			intel_sdvo->has_audio = intel_sdvo_connector->force_audio > 0;
+			intel_sdvo->has_hdmi_audio = intel_sdvo_connector->force_audio > 0;
 	}
 
 	return status;
@@ -1713,12 +1716,12 @@ intel_sdvo_set_property(struct drm_connector *connector,
 
 		intel_sdvo_connector->force_audio = val;
 
-		if (val > 0 && intel_sdvo->has_audio)
+		if (val > 0 && intel_sdvo->has_hdmi_audio)
 			return 0;
-		if (val < 0 && !intel_sdvo->has_audio)
+		if (val < 0 && !intel_sdvo->has_hdmi_audio)
 			return 0;
 
-		intel_sdvo->has_audio = val > 0;
+		intel_sdvo->has_hdmi_audio = val > 0;
 		goto done;
 	}
 
@@ -2070,6 +2073,8 @@ intel_sdvo_dvi_init(struct intel_sdvo *intel_sdvo, int device)
 		intel_sdvo_set_colorimetry(intel_sdvo,
 					   SDVO_COLORIMETRY_RGB256);
 		connector->connector_type = DRM_MODE_CONNECTOR_HDMIA;
+
+		intel_sdvo_add_hdmi_properties(intel_sdvo_connector);
 		intel_sdvo->is_hdmi = true;
 	}
 	intel_sdvo->base.clone_mask = ((1 << INTEL_SDVO_NON_TV_CLONE_BIT) |
@@ -2077,8 +2082,6 @@ intel_sdvo_dvi_init(struct intel_sdvo *intel_sdvo, int device)
 
 	intel_sdvo_connector_init(intel_sdvo_connector, intel_sdvo);
 
-	intel_sdvo_add_hdmi_properties(intel_sdvo_connector);
-
 	return true;
 }