From d1cc0ec3da23e44c23712579515494b374f111c9 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Mon, 20 Nov 2017 11:45:45 +0100
Subject: [PATCH] backlight: max8925_bl: Fix Device Tree node lookup
Git-commit: d1cc0ec3da23e44c23712579515494b374f111c9
Patch-mainline: v4.18-rc1
References: bsc#1051510

Fix child-node lookup during probe, which ended up searching the whole
device tree depth-first starting at the parent rather than just matching
on its children.

To make things worse, the parent mfd node was also prematurely freed,
while the child backlight node was leaked.

Cc: stable <stable@vger.kernel.org>     # 3.9
Fixes: 47ec340cb8e2 ("mfd: max8925: Support dt for backlight")
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/video/backlight/max8925_bl.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/video/backlight/max8925_bl.c b/drivers/video/backlight/max8925_bl.c
index 7b738d60ecc2..f3aa6088f1d9 100644
--- a/drivers/video/backlight/max8925_bl.c
+++ b/drivers/video/backlight/max8925_bl.c
@@ -116,7 +116,7 @@ static void max8925_backlight_dt_init(struct platform_device *pdev)
 	if (!pdata)
 		return;
 
-	np = of_find_node_by_name(nproot, "backlight");
+	np = of_get_child_by_name(nproot, "backlight");
 	if (!np) {
 		dev_err(&pdev->dev, "failed to find backlight node\n");
 		return;
@@ -125,6 +125,8 @@ static void max8925_backlight_dt_init(struct platform_device *pdev)
 	if (!of_property_read_u32(np, "maxim,max8925-dual-string", &val))
 		pdata->dual_string = val;
 
+	of_node_put(np);
+
 	pdev->dev.platform_data = pdata;
 }
 
-- 
2.18.0