tici: set brightness in std::async (#2347)

* set brightness in std::async

* CI
old-commit-hash: 442f2543e3

selfdrive/ui/qt/window.cc

@@ -3,6 +3,7 @@
 #include <cmath>
 #include <iostream>
 #include <fstream>
+#include <future>
 #include <signal.h>
 
 #include <QVBoxLayout>
@@ -92,29 +93,31 @@ void GLWindow::timerUpdate(){
   // Update brightness
   float clipped_brightness = std::min(1023.0f, (ui_state->light_sensor*brightness_m) + brightness_b);
   smooth_brightness = clipped_brightness * 0.01f + smooth_brightness * 0.99f;
+  int brightness = smooth_brightness;
 
-  std::ofstream brightness_control("/sys/class/backlight/panel0-backlight/brightness");
-  if (brightness_control.is_open()){
-    brightness_control << int(smooth_brightness) << "\n";
-    brightness_control.close();
-  }
-
-  ui_update(ui_state);
 
 #ifdef QCOM2
   if (ui_state->started != onroad){
     onroad = ui_state->started;
     timer->setInterval(onroad ? 50 : 1000);
+  }
 
-    int brightness = onroad ? 1023 : 0;
-    std::ofstream brightness_control("/sys/class/backlight/panel0-backlight/brightness");
-    if (brightness_control.is_open()){
-      brightness_control << int(brightness) << "\n";
-      brightness_control.close();
-    }
+  if (!ui_state->started){
+    brightness = 0;
   }
 #endif
 
+  std::async(std::launch::async,
+             [brightness]{
+               std::ofstream brightness_control("/sys/class/backlight/panel0-backlight/brightness");
+               if (brightness_control.is_open()){
+                 brightness_control << brightness << "\n";
+                 brightness_control.close();
+               }
+             });
+
+
+  ui_update(ui_state);
   update();
 }