From c51b642f813e6a38c8e1f80091d3c09950537155 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Thu, 25 Aug 2016 07:15:59 -0600
Subject: [PATCH] Fix some driver return values.  If sem_wait fails, the
 errcode is in errno, not the return value.

---
 drivers/sensors/bmg160.c   | 5 +++--
 drivers/sensors/lis3dsh.c  | 5 +++--
 drivers/sensors/lis3mdl.c  | 5 +++--
 drivers/sensors/mlx90393.c | 5 +++--
 4 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/sensors/bmg160.c b/drivers/sensors/bmg160.c
index b27fbd8777..03ad72a5d0 100644
--- a/drivers/sensors/bmg160.c
+++ b/drivers/sensors/bmg160.c
@@ -455,8 +455,9 @@ static ssize_t bmg160_read(FAR struct file *filep, FAR char *buffer,
   ret = sem_wait(&priv->datasem);
   if (ret < 0)
     {
-      snerr("ERROR: Could not aquire priv->datasem: %d\n", ret);
-      return ret;
+      int errcode = errno;
+      snerr("ERROR: Could not aquire priv->datasem: %d\n", errcode);
+      return -errcode;
     }
 
   /* Copy the sensor data into the buffer */
diff --git a/drivers/sensors/lis3dsh.c b/drivers/sensors/lis3dsh.c
index a9aa3aa9db..243f89874d 100644
--- a/drivers/sensors/lis3dsh.c
+++ b/drivers/sensors/lis3dsh.c
@@ -451,8 +451,9 @@ static ssize_t lis3dsh_read(FAR struct file *filep, FAR char *buffer,
   ret = sem_wait(&priv->datasem);
   if (ret < 0)
     {
-      snerr("ERROR: Could not aquire priv->datasem: %d\n", ret);
-      return ret;
+      int errcode = errno;
+      snerr("ERROR: Could not aquire priv->datasem: %d\n", errcode);
+      return -errcode;
     }
 
   /* Copy the sensor data into the buffer */
diff --git a/drivers/sensors/lis3mdl.c b/drivers/sensors/lis3mdl.c
index bec3f14cd2..cdb04e776e 100644
--- a/drivers/sensors/lis3mdl.c
+++ b/drivers/sensors/lis3mdl.c
@@ -494,8 +494,9 @@ static ssize_t lis3mdl_read(FAR struct file *filep, FAR char *buffer,
   ret = sem_wait(&priv->datasem);
   if (ret < 0)
     {
-      snerr("ERROR: Could not aquire priv->datasem: %d\n", ret);
-      return ret;
+      int errcode = errno;
+      snerr("ERROR: Could not aquire priv->datasem: %d\n", errcode);
+      return -errcode;
     }
 
   /* Copy the sensor data into the buffer */
diff --git a/drivers/sensors/mlx90393.c b/drivers/sensors/mlx90393.c
index 1eb9aac641..93a53ef871 100644
--- a/drivers/sensors/mlx90393.c
+++ b/drivers/sensors/mlx90393.c
@@ -486,8 +486,9 @@ static ssize_t mlx90393_read(FAR struct file *filep, FAR char *buffer,
   ret = sem_wait(&priv->datasem);
   if (ret < 0)
     {
-      snerr("ERROR: Could not aquire priv->datasem: %d\n", ret);
-      return ret;
+      int errcode = errno;
+      snerr("ERROR: Could not aquire priv->datasem: %d\n", errcode);
+      return -errcode;
     }
 
   data = (FAR struct mlx90393_sensor_data_s *)buffer;