From 6950ea4646f2dcfaacc9cd8958739b2492922f38 Mon Sep 17 00:00:00 2001
From: chao an <anchao@xiaomi.com>
Date: Thu, 3 Nov 2022 18:07:17 +0800
Subject: [PATCH] drivers/lcd/pcf8574: driver lock should in pairs

Signed-off-by: chao an <anchao@xiaomi.com>
---
 drivers/lcd/pcf8574_lcd_backpack.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/lcd/pcf8574_lcd_backpack.c b/drivers/lcd/pcf8574_lcd_backpack.c
index 6f697d6600..5eaf874c8f 100644
--- a/drivers/lcd/pcf8574_lcd_backpack.c
+++ b/drivers/lcd/pcf8574_lcd_backpack.c
@@ -1064,6 +1064,7 @@ static int pcf8574_lcd_open(FAR struct file *filep)
   nxmutex_lock(&priv->lock);
   if (priv->refs == MAX_OPENCNT)
     {
+      nxmutex_unlock(&priv->lock);
       return -EMFILE;
     }
   else