解决_tc_flush可能引起的缓冲区冲突

components/drivers/serial/serial.c

@@ -882,6 +882,7 @@ static int _get_baudrate(speed_t speed)
 
 static void _tc_flush(struct rt_serial_device *serial, int queue)
 {
+    rt_base_t level;
     int ch = -1;
     struct rt_serial_rx_fifo *rx_fifo = RT_NULL;
     struct rt_device *device = RT_NULL;
@@ -901,10 +902,12 @@ static void _tc_flush(struct rt_serial_device *serial, int queue)
             if((device->open_flag & RT_DEVICE_FLAG_INT_RX) || (device->open_flag & RT_DEVICE_FLAG_DMA_RX))
             {
                 RT_ASSERT(RT_NULL != rx_fifo);
+                level = rt_hw_interrupt_disable();
                 rt_memset(rx_fifo->buffer, 0, serial->config.bufsz);
                 rx_fifo->put_index = 0;
                 rx_fifo->get_index = 0;
                 rx_fifo->is_full = RT_FALSE;
+                rt_hw_interrupt_enable(level);
             }
             else
             {