优化调整

src/main.rs

@@ -76,7 +76,7 @@ async fn get_mac() -> HttpResponse {
         mac_address: mac,
     };
      // 在新线程中运行MQTT和串口服务
-     let mqtt_handle = tokio::spawn(async {
+     let _mqtt_handle = tokio::spawn(async {
         if let Err(e) = run_mqtt_and_serial().await {
             eprintln!("MQTT/串口服务错误: {}", e);
         }
@@ -139,11 +139,9 @@ async fn run_mqtt_and_serial() -> Result<()> {
     match serialport::new(&config.serial_port, config.baud_rate)
         .timeout(Duration::from_millis(10))
         .open() {
-        Err(e) => {
-            if e.kind() == std::io::ErrorKind::PermissionDenied {
-                eprintln!("串口 {} 已被占用", config.serial_port);
-                return Ok(());
-            }
+        Err(_e) => {
+            eprintln!("串口 {} 已被占用", config.serial_port);
+            return Ok(());
         },
         Ok(_) => {}
     }