Index: sources/device/DeviceController.cpp
===================================================================
diff -u -r80b5e8f1ebb90c03c37d90d90cd2da3bd95d6803 -rb012c6d1d980d4341faad8719dd33a0bed49b7f8
--- sources/device/DeviceController.cpp	(.../DeviceController.cpp)	(revision 80b5e8f1ebb90c03c37d90d90cd2da3bd95d6803)
+++ sources/device/DeviceController.cpp	(.../DeviceController.cpp)	(revision b012c6d1d980d4341faad8719dd33a0bed49b7f8)
@@ -63,6 +63,12 @@
     initConnections();
     startTimer(_interval);
 
+    // Add watch for event driven detection of USB insertion/removal
+    doAddDirectoryWatch(Storage::USB_Dev_Path);
+
+    // Do initial mount check on start-up
+    usbCheck();
+
     return true;
 }
 
@@ -107,6 +113,8 @@
 
     connect(&_fileSystemWatcher     , SIGNAL(        fileChanged(const QString &)),
             this                    ,   SLOT( onWatchFileChanged(const QString &)));
+    connect(&_fileSystemWatcher     , SIGNAL(        directoryChanged(const QString &)),
+            this                    ,   SLOT( onWatchDirectoryChanged(const QString &)));
 
     connect(&_ApplicationController , SIGNAL(didPOSTEthernetData    (const QString &)),
             this                    ,   SLOT( onPOSTEthernetData    (const QString &)));
@@ -187,6 +195,7 @@
             vDevice = device;
             return true; // application is deciding on the first existing drive
         }
+        device = "";
     }
     vDevice = device;
     return false;
@@ -229,11 +238,10 @@
  * \details This event handler has been re-implemented in here
  *          to receive timer events for the object
  *          for the timer which has been set to _checkInterval
- *          Runs the usbCheck on interval
  */
 void DeviceController::timerEvent(QTimerEvent *)
 {
-    usbCheck();
+    // DO NOT run usbCheck() on interval to avoid performance impact since models are regenerated
     sdcardSpaceCheck();
 }
 
@@ -244,17 +252,16 @@
  */
 void DeviceController::usbCheck()
 {
-    QString device = "";
-    usbSpaceCheck();
-    if (usbSeek(device)) {
-        if (! _umounted ) { // avoid to mount the USB which has just been unmounted
-            usbMount(device);
-        } else {            // the umount is requested?
-            usbUmount(USB_Mount_Point);
-        }
+    QString currentUSBDevice;
+    bool found = usbSeek(currentUSBDevice);
+    //DEBUG: qDebug()<< "Current usb device found " <<currentUSBDevice << " last mounted " << _lastMountedDevice << found;
+
+    if ( found && (_lastMountedDevice != currentUSBDevice)){ // found device is not the same as last device, update mount
+        usbMount(currentUSBDevice);
     } else {
-        if ( ! _removed ) {
-            usbRemove();
+        if ( !found ){ // indicates no usb device found
+            usbRemove(); // handle remove state
+            _lastMountedDevice = ""; // Clear last mounted device path
         }
     }
 }
@@ -366,14 +373,14 @@
  */
 void DeviceController::usbError(const QString &vDevice)
 {
+    //DEBUG qDebug()<<Q_FUNC_INFO << vDevice;
     // disabled coco begin validated: This needs user interaction to plug-in/out the USB device
     // has been tested manually
     QString error;
     static QString lastError;
     switch (errno) {
     case EBUSY:
         error = tr("%1 - Device or resource busy (%2)").arg(errno).arg(vDevice);
-        _mounted  = true;
     break;
 
     default:
@@ -397,7 +404,7 @@
 {
     // disabled coco begin validated: This needs user interaction to plug-in/out the USB device
     // has been tested manually
-    _umounted = true;
+    usbUmount(_lastMountedDevice);
 }
 // disabled coco end
 
@@ -436,8 +443,6 @@
     // disabled coco begin validated: This needs user interaction to plug-out the USB device
     // has been tested manually
     usbUmount(USB_Mount_Point);
-    _umounted = false;
-    _removed  = true;
     LOG_DEBUG("USB drive removed");
     emit didUSBDriveRemove();
 }
@@ -777,6 +782,25 @@
 }
 
 /*!
+ * \brief   DeviceController::ondoAddDirWatch
+ * \details The thread safe add directory watch method
+ * \param   vDirectory - The folder to add to watch.
+ */
+void DeviceController::ondoAddDirectoryWatch(const QString &vDirectory)
+{
+    QDir directory(vDirectory);
+    if ( !directory.exists()) {
+        LOG_DEBUG(DeviceError::deviceErrorText(DeviceError::eDevice_Watch_Error_NotFound, 0));
+        return;
+    }
+    if ( ! _fileSystemWatcher.addPath(vDirectory) ) {
+        LOG_DEBUG(DeviceError::deviceErrorText(DeviceError::eDevice_Watch_Error_NotAdded, 0));
+    }
+
+    //DEBUG qDebug()<<_fileSystemWatcher.directories();
+}
+
+/*!
  * \brief   DeviceController::onWatchFileChanged
  * \details This slot is called once the files being watched is updated.
  * \param   vFile - the file name.
@@ -787,6 +811,23 @@
 }
 
 /*!
+ * \brief   DeviceController::onWatchDirectoryChanged
+ * \details This slot is called once the folders being watched is updated.
+ * \param   vDirectory - the name of the directory
+ */
+void DeviceController::onWatchDirectoryChanged(const QString &vDirectory)
+{
+    if(vDirectory == Storage::USB_Dev_Path)
+    {
+        // the directory change is related to a usb device, handle update
+        usbCheck();
+    }
+
+    // pass along the signal to others
+    emit didWatchDirectoryChange(vDirectory);
+}
+
+/*!
  * \brief   DeviceController::onEventThreadChange
  * \details The signal handler for the DeviceController(this)::didEventThreadChange
  *          to start checking for the Encrypted partition readyness.
@@ -1032,6 +1073,7 @@
  */
 void DeviceController::onProcessUSBMountExitCode(int vExitCode, QProcess::ExitStatus vStatus)
 {
+    //DEBUG qDebug()<< Q_FUNC_INFO << vExitCode;
     MDeviceUSBMountResponse model;
     QByteArray deviceInfo  = _processUSBMount.readAll();
     if ( vStatus )  vExitCode   = Device::DeviceError::eDevice_Scripts_Error_Status;
@@ -1047,17 +1089,15 @@
     QString usbDevice = _deviceUSBMountRequest._data.usbDevice;
     if(_deviceUSBMountRequest._data.isMountRequest) {       // *** USB Mount
         if ( ok ) {
-            _mounted = true;
-            _removed = false;
             LOG_DEBUG(QString("USB flash drive %1 has been mounted on %2").arg(usbDevice).arg(USB_Mount_Point));
+            _lastMountedDevice = usbDevice;
             emit didUSBDriveMount();
         } else {
             usbError(usbDevice);
         }
     } else {                                                // *** USB Unmount
         if ( ok ) {
-            _mounted = false;
-         // _umounted = true; // I think it might be needed, but needs more testing.
+            //DEBUG qDebug()<< "unmounted drive " << usbDevice;
             LOG_DEBUG(QString("USB drive %2 unmounted").arg(usbDevice));
             emit didUSBDriveUmount();
         } else {