drm/nouveau/dp: probe dpcd to determine connectedness

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_connector.c

@@ -111,15 +111,15 @@ nouveau_connector_destroy(struct drm_connector *connector)
 	kfree(connector);
 }
 
-static struct nouveau_i2c_port *
-nouveau_connector_ddc_detect(struct drm_connector *connector,
-			     struct nouveau_encoder **pnv_encoder)
+static struct nouveau_encoder *
+nouveau_connector_ddc_detect(struct drm_connector *connector)
 {
 	struct drm_device *dev = connector->dev;
 	struct nouveau_connector *nv_connector = nouveau_connector(connector);
 	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nouveau_gpio *gpio = nouveau_gpio(drm->device);
-	struct nouveau_i2c_port *port = NULL;
+	struct nouveau_encoder *nv_encoder;
+	struct drm_mode_object *obj;
 	int i, panel = -ENODEV;
 
 	/* eDP panels need powering on by us (if the VBIOS doesn't default it
@@ -134,36 +134,34 @@ nouveau_connector_ddc_detect(struct drm_connector *connector,
 		}
 	}
 
-	for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
-		struct nouveau_encoder *nv_encoder;
-		struct drm_mode_object *obj;
-		int id;
-
-		id = connector->encoder_ids[i];
-		if (!id)
+	for (i = 0; nv_encoder = NULL, i < DRM_CONNECTOR_MAX_ENCODER; i++) {
+		int id = connector->encoder_ids[i];
+		if (id == 0)
 			break;
 
 		obj = drm_mode_object_find(dev, id, DRM_MODE_OBJECT_ENCODER);
 		if (!obj)
 			continue;
 		nv_encoder = nouveau_encoder(obj_to_encoder(obj));
 
-		port = nv_encoder->i2c;
-		if (port && nv_probe_i2c(port, 0x50)) {
-			*pnv_encoder = nv_encoder;
-			break;
+		if (nv_encoder->dcb->type == DCB_OUTPUT_DP) {
+			int ret = nouveau_dp_detect(nv_encoder);
+			if (ret == 0)
+				break;
+		} else
+		if (nv_encoder->i2c) {
+			if (nv_probe_i2c(nv_encoder->i2c, 0x50))
+				break;
 		}
-
-		port = NULL;
 	}
 
 	/* eDP panel not detected, restore panel power GPIO to previous
 	 * state to avoid confusing the SOR for other output types.
 	 */
-	if (!port && panel == 0)
+	if (!nv_encoder && panel == 0)
 		gpio->set(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff, panel);
 
-	return port;
+	return nv_encoder;
 }
 
 static struct nouveau_encoder *
@@ -262,8 +260,8 @@ nouveau_connector_detect(struct drm_connector *connector, bool force)
 	if (ret < 0 && ret != -EACCES)
 		return conn_status;
 
-	i2c = nouveau_connector_ddc_detect(connector, &nv_encoder);
-	if (i2c) {
+	nv_encoder = nouveau_connector_ddc_detect(connector);
+	if (nv_encoder && (i2c = nv_encoder->i2c) != NULL) {
 		nv_connector->edid = drm_get_edid(connector, &i2c->adapter);
 		drm_mode_connector_update_edid_property(connector,
 							nv_connector->edid);
@@ -273,14 +271,6 @@ nouveau_connector_detect(struct drm_connector *connector, bool force)
 			goto detect_analog;
 		}
 
-		if (nv_encoder->dcb->type == DCB_OUTPUT_DP &&
-		    !nouveau_dp_detect(to_drm_encoder(nv_encoder))) {
-			NV_ERROR(drm, "Detected %s, but failed init\n",
-				 connector->name);
-			conn_status = connector_status_disconnected;
-			goto out;
-		}
-
 		/* Override encoder type for DVI-I based on whether EDID
 		 * says the display is digital or analog, both use the
 		 * same i2c channel so the value returned from ddc_detect

drivers/gpu/drm/nouveau/nouveau_dp.c

@@ -55,23 +55,22 @@ nouveau_dp_probe_oui(struct drm_device *dev, struct nouveau_i2c_port *auxch,
 
 }
 
-bool
-nouveau_dp_detect(struct drm_encoder *encoder)
+int
+nouveau_dp_detect(struct nouveau_encoder *nv_encoder)
 {
-	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
-	struct drm_device *dev = encoder->dev;
+	struct drm_device *dev = nv_encoder->base.base.dev;
 	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nouveau_i2c_port *auxch;
 	u8 *dpcd = nv_encoder->dp.dpcd;
 	int ret;
 
 	auxch = nv_encoder->i2c;
 	if (!auxch)
-		return false;
+		return -ENODEV;
 
 	ret = nv_rdaux(auxch, DP_DPCD_REV, dpcd, 8);
 	if (ret)
-		return false;
+		return ret;
 
 	nv_encoder->dp.link_bw = 27000 * dpcd[1];
 	nv_encoder->dp.link_nr = dpcd[2] & DP_MAX_LANE_COUNT_MASK;
@@ -91,6 +90,5 @@ nouveau_dp_detect(struct drm_encoder *encoder)
 		     nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);
 
 	nouveau_dp_probe_oui(dev, auxch, dpcd);
-
-	return true;
+	return 0;
 }

drivers/gpu/drm/nouveau/nouveau_encoder.h

@@ -85,9 +85,7 @@ get_slave_funcs(struct drm_encoder *enc)
 }
 
 /* nouveau_dp.c */
-bool nouveau_dp_detect(struct drm_encoder *);
-void nouveau_dp_dpms(struct drm_encoder *, int mode, u32 datarate,
-		     struct nouveau_object *);
+int nouveau_dp_detect(struct nouveau_encoder *);
 
 struct nouveau_connector *
 nouveau_encoder_connector_get(struct nouveau_encoder *encoder);