drm/nouveau: ignore connector type when deciding digital/analog on DVI-I

If the connector table is lying, which it often does on the boards of a
particular manufacturer, we may end up doing the wrong thing.  Listen
to the encoder table instead, it's more reliable.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_connector.c

@@ -40,7 +40,7 @@
 static void nouveau_connector_hotplug(void *, int);
 
 static struct nouveau_encoder *
-find_encoder_by_type(struct drm_connector *connector, int type)
+find_encoder(struct drm_connector *connector, int type)
 {
 	struct drm_device *dev = connector->dev;
 	struct nouveau_encoder *nv_encoder;
@@ -170,8 +170,8 @@ nouveau_connector_of_detect(struct drm_connector *connector)
 	struct device_node *cn, *dn = pci_device_to_OF_node(dev->pdev);
 
 	if (!dn ||
-	    !((nv_encoder = find_encoder_by_type(connector, OUTPUT_TMDS)) ||
-	      (nv_encoder = find_encoder_by_type(connector, OUTPUT_ANALOG))))
+	    !((nv_encoder = find_encoder(connector, OUTPUT_TMDS)) ||
+	      (nv_encoder = find_encoder(connector, OUTPUT_ANALOG))))
 		return NULL;
 
 	for_each_child_of_node(dn, cn) {
@@ -233,6 +233,7 @@ nouveau_connector_detect(struct drm_connector *connector, bool force)
 	struct drm_device *dev = connector->dev;
 	struct nouveau_connector *nv_connector = nouveau_connector(connector);
 	struct nouveau_encoder *nv_encoder = NULL;
+	struct nouveau_encoder *nv_partner;
 	struct nouveau_i2c_chan *i2c;
 	int type;
 
@@ -266,19 +267,22 @@ nouveau_connector_detect(struct drm_connector *connector, bool force)
 		 * same i2c channel so the value returned from ddc_detect
 		 * isn't necessarily correct.
 		 */
-		if (nv_connector->dcb->type == DCB_CONNECTOR_DVI_I) {
+		nv_partner = NULL;
+		if (nv_encoder->dcb->type == OUTPUT_TMDS)
+			nv_partner = find_encoder(connector, OUTPUT_ANALOG);
+		if (nv_encoder->dcb->type == OUTPUT_ANALOG)
+			nv_partner = find_encoder(connector, OUTPUT_TMDS);
+
+		if (nv_partner && ((nv_encoder->dcb->type == OUTPUT_ANALOG &&
+				    nv_partner->dcb->type == OUTPUT_TMDS) ||
+				   (nv_encoder->dcb->type == OUTPUT_TMDS &&
+				    nv_partner->dcb->type == OUTPUT_ANALOG))) {
 			if (nv_connector->edid->input & DRM_EDID_INPUT_DIGITAL)
 				type = OUTPUT_TMDS;
 			else
 				type = OUTPUT_ANALOG;
 
-			nv_encoder = find_encoder_by_type(connector, type);
-			if (!nv_encoder) {
-				NV_ERROR(dev, "Detected %d encoder on %s, "
-					      "but no object!\n", type,
-					 drm_get_connector_name(connector));
-				return connector_status_disconnected;
-			}
+			nv_encoder = find_encoder(connector, type);
 		}
 
 		nouveau_connector_set_encoder(connector, nv_encoder);
@@ -292,9 +296,9 @@ nouveau_connector_detect(struct drm_connector *connector, bool force)
 	}
 
 detect_analog:
-	nv_encoder = find_encoder_by_type(connector, OUTPUT_ANALOG);
+	nv_encoder = find_encoder(connector, OUTPUT_ANALOG);
 	if (!nv_encoder && !nouveau_tv_disable)
-		nv_encoder = find_encoder_by_type(connector, OUTPUT_TV);
+		nv_encoder = find_encoder(connector, OUTPUT_TV);
 	if (nv_encoder && force) {
 		struct drm_encoder *encoder = to_drm_encoder(nv_encoder);
 		struct drm_encoder_helper_funcs *helper =
@@ -327,7 +331,7 @@ nouveau_connector_detect_lvds(struct drm_connector *connector, bool force)
 		nv_connector->edid = NULL;
 	}
 
-	nv_encoder = find_encoder_by_type(connector, OUTPUT_LVDS);
+	nv_encoder = find_encoder(connector, OUTPUT_LVDS);
 	if (!nv_encoder)
 		return connector_status_disconnected;
 
@@ -405,7 +409,7 @@ nouveau_connector_force(struct drm_connector *connector)
 	} else
 		type = OUTPUT_ANY;
 
-	nv_encoder = find_encoder_by_type(connector, type);
+	nv_encoder = find_encoder(connector, type);
 	if (!nv_encoder) {
 		NV_ERROR(connector->dev, "can't find encoder to force %s on!\n",
 			 drm_get_connector_name(connector));