Postpone parameter updates for a bit.

src/Camera/QGCCameraControl.cc

@@ -984,9 +984,24 @@ QGCCameraControl::_updateRanges(Fact* pFact)
     //-- Parameter update requests
     if(_requestUpdates.contains(pFact->name())) {
         foreach(QString param, _requestUpdates[pFact->name()]) {
-            _paramIO[param]->paramRequest();
+            if(!_updatesToRequest.contains(param)) {
+                _updatesToRequest << param;
+            }
         }
     }
+    if(_updatesToRequest.size()) {
+        QTimer::singleShot(500, this, &QGCCameraControl::_requestParamUpdates);
+    }
+}
+
+//-----------------------------------------------------------------------------
+void
+QGCCameraControl::_requestParamUpdates()
+{
+    foreach(QString param, _updatesToRequest) {
+        _paramIO[param]->paramRequest();
+    }
+    _updatesToRequest.clear();
 }
 
 //-----------------------------------------------------------------------------

src/Camera/QGCCameraControl.h

@@ -166,6 +166,7 @@ private slots:
     void    _initWhenReady                  ();
     void    _requestCameraSettings          ();
     void    _requestAllParameters           ();
+    void    _requestParamUpdates            ();
     void    _requestCaptureStatus           ();
     void    _requestStorageInfo             ();
     void    _downloadFinished               ();
@@ -219,4 +220,5 @@ protected:
     int                                 _captureInfoRetries;
     //-- Parameters that require a full update
     QMap<QString, QStringList>          _requestUpdates;
+    QStringList                         _updatesToRequest;
 };