From caeea1f89335bc093e3eaf319ad459337d9b1889 Mon Sep 17 00:00:00 2001
From: boxuesong <545934173@qq.com>
Date: Thu, 18 Aug 2022 15:41:39 +0800
Subject: [PATCH] =?UTF-8?q?=E8=A7=A3=E5=86=B3=E6=8E=A7=E5=88=B6=E5=8F=B0?=
 =?UTF-8?q?=E6=97=A0=E6=B3=95=E8=BE=93=E5=85=A5bug?=
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        rt_uint16_t old_flag = _console_device->open_flag;

        _console_device->open_flag |= RT_DEVICE_FLAG_STREAM;
        rt_device_write(_console_device, 0, str, rt_strlen(str));
        _console_device->open_flag = old_flag;

        当一个线程正在执行 rt_device_write(_console_device, 0, str, rt_strlen(str));函数时，一个高优先级线程
抢占当前线程并修改 _console_device->open_flag（修改为RT_DEVICE_FLAG_INT_RX，之前不是中断接收），
高优先级线程执行完后，继续执行以前线程，此时old_flag与_console_device->open_flag不一致，执行
_console_device->open_flag = old_flag;后_console_device->open_flag新的值被覆盖。控制台串口实际配置
成硬件中断接收，因为_console_device->open_flag值被修改为不是中断，最后导致控制台串口无法接收任何数据
输入。
---
 src/kservice.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/kservice.c b/src/kservice.c
index ea9bd87b45..4c85af0bba 100644
--- a/src/kservice.c
+++ b/src/kservice.c
@@ -1175,7 +1175,7 @@ void rt_kputs(const char *str)
 
         _console_device->open_flag |= RT_DEVICE_FLAG_STREAM;
         rt_device_write(_console_device, 0, str, rt_strlen(str));
-        _console_device->open_flag = old_flag;
+        _console_device->open_flag ^= (~old_flag & RT_DEVICE_FLAG_STREAM);
     }
 #else
     rt_hw_console_output(str);
@@ -1213,7 +1213,7 @@ void rt_kprintf(const char *fmt, ...)
 
         _console_device->open_flag |= RT_DEVICE_FLAG_STREAM;
         rt_device_write(_console_device, 0, rt_log_buf, length);
-        _console_device->open_flag = old_flag;
+        _console_device->open_flag ^= (~old_flag & RT_DEVICE_FLAG_STREAM);
     }
 #else
     rt_hw_console_output(rt_log_buf);