From fef7abb5989c9d9186f405e8d43209a7789f2bdf Mon Sep 17 00:00:00 2001
From: raiden00pl <raiden00pl@gmail.com>
Date: Fri, 27 Mar 2020 16:25:33 +0100
Subject: [PATCH] arch/arm/src/nrf52/nrf52_i2c.c: protect the I2C transfer with
 a semaphore

---
 arch/arm/src/nrf52/nrf52_i2c.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arm/src/nrf52/nrf52_i2c.c b/arch/arm/src/nrf52/nrf52_i2c.c
index 4da303fddf5..0285d8e6238 100644
--- a/arch/arm/src/nrf52/nrf52_i2c.c
+++ b/arch/arm/src/nrf52/nrf52_i2c.c
@@ -223,6 +223,12 @@ static int nrf52_i2c_transfer(FAR struct i2c_master_s *dev,
   uint32_t regval = 0;
   int      ret = OK;
 
+  ret = nxsem_wait(&priv->sem_excl);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
   /* Reset ptr and dcnt */
 
   priv->dcnt = 0;
@@ -397,7 +403,8 @@ static int nrf52_i2c_transfer(FAR struct i2c_master_s *dev,
 #endif
 
 errout:
-    return ret;
+  nxsem_post(&priv->sem_excl);
+  return ret;
 }
 
 /****************************************************************************