From f5d9276434c1ab7d16bab8e22d5908a126477240 Mon Sep 17 00:00:00 2001
From: chenyong <1521761801@qq.com>
Date: Fri, 3 Aug 2018 16:11:31 +0800
Subject: [PATCH] [net][at] Add AT serial device receive data length judgment.

---
 components/net/at/src/at_client.c | 6 +++++-
 components/net/at/src/at_server.c | 5 ++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/components/net/at/src/at_client.c b/components/net/at/src/at_client.c
index c2002d8094..dd866fdcb0 100644
--- a/components/net/at/src/at_client.c
+++ b/components/net/at/src/at_client.c
@@ -577,7 +577,11 @@ static void client_parser(at_client_t client)
 
 static rt_err_t at_client_rx_ind(rt_device_t dev, rt_size_t size)
 {
-    rt_sem_release(at_client_local->rx_notice);
+    if (size > 0)
+    {
+        rt_sem_release(at_client_local->rx_notice);
+    }
+
     return RT_EOK;
 }
 
diff --git a/components/net/at/src/at_server.c b/components/net/at/src/at_server.c
index 639739d9c2..a148a20ab0 100644
--- a/components/net/at/src/at_server.c
+++ b/components/net/at/src/at_server.c
@@ -433,7 +433,10 @@ __retry:
 
 static rt_err_t at_rx_ind(rt_device_t dev, rt_size_t size)
 {
-    rt_sem_release(at_server_local->rx_notice);
+    if (size > 0)
+    {
+        rt_sem_release(at_server_local->rx_notice);
+    }
 
     return RT_EOK;
 }