drm/rockchip: dw-mipi-dsi: defer probe if panel is not loaded

This ensures that the output resolution is known before fbcon loads.
mipi_dsi_host_register() is moved above dw_mipi_dsi_register() to
simplify error cleanup since the order of these operations does not
matter.
Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170224125506.21533-22-john@metanate.com

drivers/gpu/drm/rockchip/dw-mipi-dsi.c

@@ -1189,12 +1189,27 @@ static int dw_mipi_dsi_bind(struct device *dev, struct device *master,
 		goto err_pllref;
 	}
 
-	dev_set_drvdata(dev, dsi);
-
 	dsi->dsi_host.ops = &dw_mipi_dsi_host_ops;
 	dsi->dsi_host.dev = dev;
-	return mipi_dsi_host_register(&dsi->dsi_host);
+	ret = mipi_dsi_host_register(&dsi->dsi_host);
+	if (ret) {
+		dev_err(dev, "Failed to register MIPI host: %d\n", ret);
+		goto err_cleanup;
+	}
+
+	if (!dsi->panel) {
+		ret = -EPROBE_DEFER;
+		goto err_mipi_dsi_host;
+	}
 
+	dev_set_drvdata(dev, dsi);
+	return 0;
+
+err_mipi_dsi_host:
+	mipi_dsi_host_unregister(&dsi->dsi_host);
+err_cleanup:
+	drm_encoder_cleanup(&dsi->encoder);
+	drm_connector_cleanup(&dsi->connector);
 err_pllref:
 	clk_disable_unprepare(dsi->pllref_clk);
 	return ret;