PlanManager: Improve timeout behavior during Mission Transfer

This patch fixes runtime issues which are observed
on 900MHz ELRS.

During mission download from the vehicle, repeat timeout
occurs, causing mixup of request-response pairs which
results in sequence errors of mission items.
The repeat timeout is therefore increased to 1.5 seconds.
GCS based message repetition eventually bites with ELRS
stubborn sender feature.

During mission upload to the vehicle, the regular timeout
of 1.5 seconds is too tight and causes reported errors about
not all mission items retrieved by vehicle.
Therefore a separate timeout for MISSION_REQUEST_INT service
is added with a value of 2.5 seconds which seems appropriate.

For clarity the word default is added to the name of the
original timeout values.

src/MissionManager/PlanManager.cc

@@ -247,18 +247,19 @@ void PlanManager::_startAckTimeout(AckType_t ack)
     switch (ack) {
     case AckMissionItem:
         // We are actively trying to get the mission item, so we don't want to wait as long.
-        _ackTimeoutTimer->setInterval(_retryTimeoutMilliseconds);
+        _ackTimeoutTimer->setInterval(_retryTimeoutDefaultMilliseconds);
+        break;
+    case AckMissionRequest:
+        _ackTimeoutTimer->setInterval(_ackTimeoutMissionRequestMilliseconds);
         break;
     case AckNone:
         // FALLTHROUGH
     case AckMissionCount:
         // FALLTHROUGH
-    case AckMissionRequest:
-        // FALLTHROUGH
     case AckMissionClearAll:
         // FALLTHROUGH
     case AckGuidedItem:
-        _ackTimeoutTimer->setInterval(_ackTimeoutMilliseconds);
+        _ackTimeoutTimer->setInterval(_ackTimeoutDefaultMilliseconds);
         break;
     }
 

src/MissionManager/PlanManager.h

@@ -68,9 +68,12 @@ class PlanManager : public QObject
 
     // These values are public so the unit test can set appropriate signal wait times
     // When passively waiting for a mission process, use a longer timeout.
-    static const int _ackTimeoutMilliseconds = 1500;
+    static const int _ackTimeoutDefaultMilliseconds = 1500;
+    // When uploading a mission plan, use a longer timeout to cope with low
+    // bandwidth links, i.e. ELRS 900Mhz.
+    static const int _ackTimeoutMissionRequestMilliseconds = 2500;
     // When actively retrying to request mission items, use a shorter timeout instead.
-    static const int _retryTimeoutMilliseconds = 250;
+    static const int _retryTimeoutDefaultMilliseconds = 1500;
     static const int _maxRetryCount = 5;
 
 signals:

test/MissionManager/MissionControllerManagerTest.h

@@ -72,7 +72,7 @@ protected slots:
     static const size_t _cMissionManagerSignals = maxSignalIndex;
     const char*         _rgMissionManagerSignals[_cMissionManagerSignals];
 
-    static const int _missionManagerSignalWaitTime = MissionManager::_ackTimeoutMilliseconds * MissionManager::_maxRetryCount * 2;
+    static const int _missionManagerSignalWaitTime = MissionManager::_ackTimeoutDefaultMilliseconds * MissionManager::_maxRetryCount * 2;
 };
 
 #endif