From aa1fe742927207f22222bbdfc167eb996be62832 Mon Sep 17 00:00:00 2001
From: Sean Paul <seanpaul@chromium.org>
Date: Wed, 20 Sep 2017 17:13:56 -0700
Subject: [PATCH 82/86] drm/rockchip: Fix uninitialized use of ret

Git-commit: 6bf2e0324b9376512b0b9bf5c5c4b383afd419ec
Patch-mainline: Queued
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
References: fate#323912

If there are no children for lvds, ret is used uninitialized. This patch
initializes ret and returns an error if the port has no children.

Fixes: 34cc0aa25456 ("drm/rockchip: Add support for Rockchip Soc LVDS")
Cc: Mark Yao <mark.yao@rock-chips.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-rockchip@lists.infradead.org
Reviewed-by: Mark Yao <mark.yao@rock-chips.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170921001408.1839-1-seanpaul@chromium.org
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
 drivers/gpu/drm/rockchip/rockchip_lvds.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_lvds.c b/drivers/gpu/drm/rockchip/rockchip_lvds.c
index c5fbe533796c..84911bdc27d1 100644
--- a/drivers/gpu/drm/rockchip/rockchip_lvds.c
+++ b/drivers/gpu/drm/rockchip/rockchip_lvds.c
@@ -346,7 +346,7 @@ static int rockchip_lvds_bind(struct device *dev, struct device *master,
 	struct drm_connector *connector;
 	struct device_node *remote = NULL;
 	struct device_node  *port, *endpoint;
-	int ret;
+	int ret = 0, child_count = 0;
 	const char *name;
 	u32 endpoint_id;
 
@@ -358,15 +358,20 @@ static int rockchip_lvds_bind(struct device *dev, struct device *master,
 		return -EINVAL;
 	}
 	for_each_child_of_node(port, endpoint) {
+		child_count++;
 		of_property_read_u32(endpoint, "reg", &endpoint_id);
 		ret = drm_of_find_panel_or_bridge(dev->of_node, 1, endpoint_id,
 						  &lvds->panel, &lvds->bridge);
 		if (!ret)
 			break;
 	}
-	if (ret) {
+	if (!child_count) {
+		DRM_DEV_ERROR(dev, "lvds port does not have any children\n");
+		ret = -EINVAL;
+		goto err_put_port;
+	} else if (ret) {
 		DRM_DEV_ERROR(dev, "failed to find panel and bridge node\n");
-		ret  = -EPROBE_DEFER;
+		ret = -EPROBE_DEFER;
 		goto err_put_port;
 	}
 	if (lvds->panel)
-- 
2.11.0