after dc-download, check if device-controller reboots successfully

DownloadDCFirmware/update.cpp

@@ -450,16 +450,25 @@ int Update::run() {
             qCritical() << "DownloadThread::run(): last result" << (int)sendStatus(m_hw->bl_wasSendingDataOK());
 #endif
         }
-        // TODO
         stopBootloader();   // there is no harm in stopping the bootloader even
                             // if starting the bootloader failed
-        qInfo() << nextTimePoint().toUtf8().constData() << "<DC-UPDATE-SUCCESS>";
 
+        // check if update was successful
         if (!m_debug) {
             m_hw->dc_autoRequest(true); //restart dc_autoRequest after download else E255!
         }
 
-        return -(int)Result::SUCCESS;
+        for (int i = 0; i < 3; ++i) {
+            qInfo() << "waiting for device controller restart...(" << i << ")";
+            QThread::sleep(20);
+
+            resetDeviceController();
+            if (startBootloader()) {
+                qInfo() << nextTimePoint().toUtf8().constData() << "<DC-UPDATE-SUCCESS>";
+                stopBootloader();
+                return -(int)Result::SUCCESS;
+            }
+        }
     }
 
     qInfo() << nextTimePoint().toUtf8().constData() << "<DC-UPDATE-FAILURE>";