From: Marek Szyprowski <m.szyprowski@samsung.com>
Date: Mon, 5 Mar 2018 09:57:41 +0100
Subject: drm/bridge: analogix_dp: Don't create useless connectors
Git-commit: 2e9b3e74b4a184f657995cf28963f72531c7a420
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

If there is another bridge after analogix_dp, then the connector object
should not be created. This fixes following timeouts on Exynos5420-based
Chromebook2 Peach-PIT board during boot:

exynos-dp 145b0000.dp-controller: AUX CH cmd reply timeout!
exynos-dp 145b0000.dp-controller: AUX CH enable timeout!
exynos-dp 145b0000.dp-controller: AUX CH enable timeout!
exynos-dp 145b0000.dp-controller: AUX CH enable timeout!
exynos-dp 145b0000.dp-controller: AUX CH enable timeout!

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180305085741.18896-4-m.szyprowski@samsung.com

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/bridge/analogix/analogix_dp_core.c |   29 +++++++++++----------
 drivers/gpu/drm/exynos/exynos_dp.c                 |    1 
 include/drm/bridge/analogix_dp.h                   |    1 
 3 files changed, 18 insertions(+), 13 deletions(-)

--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -1012,27 +1012,30 @@ static int analogix_dp_bridge_attach(str
 {
 	struct analogix_dp_device *dp = bridge->driver_private;
 	struct drm_encoder *encoder = dp->encoder;
-	struct drm_connector *connector = &dp->connector;
-	int ret;
+	struct drm_connector *connector = NULL;
+	int ret = 0;
 
 	if (!bridge->encoder) {
 		DRM_ERROR("Parent encoder object not found");
 		return -ENODEV;
 	}
 
-	connector->polled = DRM_CONNECTOR_POLL_HPD;
+	if (!dp->plat_data->skip_connector) {
+		connector = &dp->connector;
+		connector->polled = DRM_CONNECTOR_POLL_HPD;
 
-	ret = drm_connector_init(dp->drm_dev, connector,
-				 &analogix_dp_connector_funcs,
-				 DRM_MODE_CONNECTOR_eDP);
-	if (ret) {
-		DRM_ERROR("Failed to initialize connector with drm\n");
-		return ret;
-	}
+		ret = drm_connector_init(dp->drm_dev, connector,
+					 &analogix_dp_connector_funcs,
+					 DRM_MODE_CONNECTOR_eDP);
+		if (ret) {
+			DRM_ERROR("Failed to initialize connector with drm\n");
+			return ret;
+		}
 
-	drm_connector_helper_add(connector,
-				 &analogix_dp_connector_helper_funcs);
-	drm_mode_connector_attach_encoder(connector, encoder);
+		drm_connector_helper_add(connector,
+					 &analogix_dp_connector_helper_funcs);
+		drm_mode_connector_attach_encoder(connector, encoder);
+	}
 
 	/*
 	 * NOTE: the connector registration is implemented in analogix
--- a/drivers/gpu/drm/exynos/exynos_dp.c
+++ b/drivers/gpu/drm/exynos/exynos_dp.c
@@ -244,6 +244,7 @@ static int exynos_dp_probe(struct platfo
 
 	/* The remote port can be either a panel or a bridge */
 	dp->plat_data.panel = panel;
+	dp->plat_data.skip_connector = !!bridge;
 	dp->ptn_bridge = bridge;
 
 out:
--- a/include/drm/bridge/analogix_dp.h
+++ b/include/drm/bridge/analogix_dp.h
@@ -31,6 +31,7 @@ struct analogix_dp_plat_data {
 	struct drm_panel *panel;
 	struct drm_encoder *encoder;
 	struct drm_connector *connector;
+	bool skip_connector;
 
 	int (*power_on)(struct analogix_dp_plat_data *);
 	int (*power_off)(struct analogix_dp_plat_data *);