hardwared: disable power save when screen is on (#36466)

system/hardware/hardwared.py

@@ -195,6 +195,7 @@ def hardware_thread(end_event, hw_queue) -> None:
   should_start_prev = False
   in_car = False
   engaged_prev = False
+  pwrsave = False
   offroad_cycle_count = 0
 
   params = Params()
@@ -341,7 +342,6 @@ def hardware_thread(end_event, hw_queue) -> None:
     if should_start != should_start_prev or (count == 0):
       params.put_bool("IsEngaged", False)
       engaged_prev = False
-      HARDWARE.set_power_save(not should_start)
 
     if sm.updated['selfdriveState']:
       engaged = sm['selfdriveState'].enabled
@@ -355,6 +355,11 @@ def hardware_thread(end_event, hw_queue) -> None:
       except Exception:
         pass
 
+    should_pwrsave = not onroad_conditions["ignition"] and msg.deviceState.screenBrightnessPercent < 1e-3
+    if should_pwrsave != pwrsave or (count == 0):
+      HARDWARE.set_power_save(should_pwrsave)
+    pwrsave = should_pwrsave
+
     if should_start:
       off_ts = None
       if started_ts is None: