drm/msm/dsi: move next bridge acquisition to dsi_bind

Currently the MSM DSI driver looks for the next bridge during
msm_dsi_modeset_init(). If the bridge is not registered at that point,
this might result in -EPROBE_DEFER, which can be problematic that late
during the device probe process. Move next bridge acquisition to the
dsi_bind state so that probe deferral is returned as early as possible.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/582210/
Link: https://lore.kernel.org/r/20240309-fd-dsi-cleanup-bridges-v1-2-962ebdba82ed@linaro.org

drivers/gpu/drm/msm/dsi/dsi.c

@@ -120,6 +120,22 @@ static int dsi_bind(struct device *dev, struct device *master, void *data)
 	struct msm_drm_private *priv = dev_get_drvdata(master);
 	struct msm_dsi *msm_dsi = dev_get_drvdata(dev);
 
+	/*
+	 * Next bridge doesn't exist for the secondary DSI host in a bonded
+	 * pair.
+	 */
+	if (!msm_dsi_is_bonded_dsi(msm_dsi) ||
+	    msm_dsi_is_master_dsi(msm_dsi)) {
+		struct drm_bridge *ext_bridge;
+
+		ext_bridge = devm_drm_of_get_bridge(&msm_dsi->pdev->dev,
+						    msm_dsi->pdev->dev.of_node, 1, 0);
+		if (IS_ERR(ext_bridge))
+			return PTR_ERR(ext_bridge);
+
+		msm_dsi->next_bridge = ext_bridge;
+	}
+
 	priv->dsi[msm_dsi->id] = msm_dsi;
 
 	return 0;

drivers/gpu/drm/msm/dsi/dsi.h

@@ -38,6 +38,8 @@ struct msm_dsi {
 	struct mipi_dsi_host *host;
 	struct msm_dsi_phy *phy;
 
+	struct drm_bridge *next_bridge;
+
 	struct device *phy_dev;
 	bool phy_enabled;
 

drivers/gpu/drm/msm/dsi/dsi_manager.c

@@ -464,18 +464,12 @@ int msm_dsi_manager_ext_bridge_init(u8 id, struct drm_bridge *int_bridge)
 	struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
 	struct drm_device *dev = msm_dsi->dev;
 	struct drm_encoder *encoder;
-	struct drm_bridge *ext_bridge;
 	struct drm_connector *connector;
 	int ret;
 
-	ext_bridge = devm_drm_of_get_bridge(&msm_dsi->pdev->dev,
-					    msm_dsi->pdev->dev.of_node, 1, 0);
-	if (IS_ERR(ext_bridge))
-		return PTR_ERR(ext_bridge);
-
 	encoder = int_bridge->encoder;
 
-	ret = drm_bridge_attach(encoder, ext_bridge, int_bridge,
+	ret = drm_bridge_attach(encoder, msm_dsi->next_bridge, int_bridge,
 			DRM_BRIDGE_ATTACH_NO_CONNECTOR);
 	if (ret)
 		return ret;