Add informSearchFailed method to update GPS power state handling (#10394)

src/gps/GPS.cpp

@@ -1017,10 +1017,13 @@ void GPS::up()
     setPowerState(GPS_ACTIVE);
 }
 
-// We've got a GPS lock. Enter a low power state, potentially.
+// We've finished a GPS search cycle (lock or timeout). Enter a low power state, potentially.
 void GPS::down()
 {
-    scheduling.informGotLock();
+    if (hasValidLocation)
+        scheduling.informGotLock();
+    else
+        scheduling.informSearchFailed();
     uint32_t predictedSearchDuration = scheduling.predictedSearchDurationMs();
     uint32_t sleepTime = scheduling.msUntilNextSearch();
     uint32_t updateInterval = Default::getConfiguredOrDefaultMs(config.position.gps_update_interval);

src/gps/GPSUpdateScheduling.cpp

@@ -17,6 +17,16 @@ void GPSUpdateScheduling::informGotLock()
     updateLockTimePrediction();
 }
 
+// Search finished without obtaining a fix. We still need to mark the end time so
+// the next sleep is timed correctly, but we must not feed the timeout duration
+// into predictedMsToGetLock — doing so poisons msUntilNextSearch() and causes
+// down() to fall into GPS_IDLE, leaving the chip awake on subsequent indoor cycles.
+void GPSUpdateScheduling::informSearchFailed()
+{
+    searchEndedMs = millis();
+    LOG_DEBUG("GPS search ended without fix after %us", (searchEndedMs - searchStartedMs) / 1000);
+}
+
 // Clear old lock-time prediction data.
 // When re-enabling GPS with user button.
 void GPSUpdateScheduling::reset()

src/gps/GPSUpdateScheduling.h

@@ -8,7 +8,8 @@ class GPSUpdateScheduling
   public:
     // Marks the time of these events, for calculation use
     void informSearching();
-    void informGotLock(); // Predicted lock-time is recalculated here
+    void informGotLock();      // Predicted lock-time is recalculated here
+    void informSearchFailed(); // Search ended without a fix; prediction is left untouched
 
     void reset();           // Reset the prediction - after GPS::disable() / GPS::enable()
     bool isUpdateDue();     // Is it time to begin searching for a GPS position?