VOL-1132 Fix auditing and resynchronizing to proceed to diffs_found

Change-Id: Idcf39dfeef139ea50ac3cfce24eb2d94240f2faf
diff --git a/voltha/extensions/omci/state_machines/mib_sync.py b/voltha/extensions/omci/state_machines/mib_sync.py
index 58ec377..c725cce 100644
--- a/voltha/extensions/omci/state_machines/mib_sync.py
+++ b/voltha/extensions/omci/state_machines/mib_sync.py
@@ -511,9 +511,9 @@
             attr_diffs = results.get('attr-diffs')
 
             self._current_task = None
-            self._on_olt_only_diffs = on_olt_only if len(on_olt_only) else None
-            self._on_onu_only_diffs = on_onu_only if len(on_onu_only) else None
-            self._attr_diffs = attr_diffs if len(attr_diffs) else None
+            self._on_olt_only_diffs = on_olt_only if on_olt_only and len(on_olt_only) else None
+            self._on_onu_only_diffs = on_onu_only if on_onu_only and len(on_onu_only) else None
+            self._attr_diffs = attr_diffs if attr_diffs and len(attr_diffs) else None
 
             if all(diff is None for diff in [self._on_olt_only_diffs,
                                              self._on_onu_only_diffs,
diff --git a/voltha/extensions/omci/tasks/mib_resync_task.py b/voltha/extensions/omci/tasks/mib_resync_task.py
index 6a7c899..30a888f 100644
--- a/voltha/extensions/omci/tasks/mib_resync_task.py
+++ b/voltha/extensions/omci/tasks/mib_resync_task.py
@@ -184,8 +184,8 @@
                             db_copy = None
                             break
 
-                except TimeoutError as e:
-                    self.log.warn('timeout', e=e)
+                except (TimeoutError, ValueError) as e:
+                    self.log.warn('timeout-or-value-error', e=e)
                     if retries >= max_tries:
                         raise
 
@@ -195,6 +195,8 @@
 
                 # Get a snapshot of the local MIB database
                 db_copy = self._device.query_mib()
+                # if we made it this far, no need to keep trying
+                break
 
         except Exception as e:
             self.log.exception('mib-resync', e=e)