waiting for the OLT to go down in OLT soft reboot tests

Change-Id: I438fca46d2e9096d8cca541d59809ba3082b3a4b
diff --git a/VERSION b/VERSION
index 49cdd66..1f7da99 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.7.6
+2.7.7
diff --git a/tests/dt-workflow/Voltha_DT_MultiOLT_Tests.robot b/tests/dt-workflow/Voltha_DT_MultiOLT_Tests.robot
index b99bccd..d1c1593 100644
--- a/tests/dt-workflow/Voltha_DT_MultiOLT_Tests.robot
+++ b/tests/dt-workflow/Voltha_DT_MultiOLT_Tests.robot
@@ -130,6 +130,9 @@
     ...    REACHABLE    ${olt_serial_number}
     # Reboot the OLT using "voltctl device reboot" command
     Reboot Device    ${olt_device_id}
+    # Wait for the OLT to actually go down
+    Wait Until Keyword Succeeds    360s    5s    Validate OLT Device    ENABLED    UNKNOWN    UNREACHABLE
+    ...    ${olt_serial_number}
     # validate that the ONUs on the other OLTs are still functional
     Verify ping is successful for ONUs not on this OLT     ${num_all_onus}    ${olt_device_id}
     #Verify that ping fails for the ONUs where the OLT has been rebooted
diff --git a/tests/functional/Voltha_FailureScenarios.robot b/tests/functional/Voltha_FailureScenarios.robot
index c50c3ca..5d12082 100644
--- a/tests/functional/Voltha_FailureScenarios.robot
+++ b/tests/functional/Voltha_FailureScenarios.robot
@@ -592,6 +592,9 @@
         ...    REACHABLE    ${olt_serial_number}
         # Reboot the OLT using "voltctl device reboot" command
         Reboot Device    ${olt_device_id}
+        # Wait for the OLT to actually go down
+        Wait Until Keyword Succeeds    360s    5s    Validate OLT Device    ENABLED    UNKNOWN    UNREACHABLE
+        ...    ${olt_serial_number}
     END
     #Verify that ping fails
     FOR    ${I}    IN RANGE    0    ${num_all_onus}
diff --git a/tests/functional/Voltha_FailureScenarios2.robot b/tests/functional/Voltha_FailureScenarios2.robot
index ab21938..1cf802d 100644
--- a/tests/functional/Voltha_FailureScenarios2.robot
+++ b/tests/functional/Voltha_FailureScenarios2.robot
@@ -69,6 +69,9 @@
     Wait Until Keyword Succeeds    ${timeout}    2s    Perform Sanity Test
     # Reboot the OLT using "voltctl device reboot" command
     Reboot Device    ${olt_device_id}
+    # Wait for the OLT to actually go down
+    Wait Until Keyword Succeeds    360s    5s    Validate OLT Device    ENABLED    UNKNOWN    UNREACHABLE
+    ...    ${olt_serial_number}
     #Verify that ping fails
     FOR    ${I}    IN RANGE    0    ${num_onus}
         ${src}=    Set Variable    ${hosts.src[${I}]}
diff --git a/tests/functional/Voltha_MultiOLT_Tests.robot b/tests/functional/Voltha_MultiOLT_Tests.robot
index 2bec3c2..c55a8cc 100644
--- a/tests/functional/Voltha_MultiOLT_Tests.robot
+++ b/tests/functional/Voltha_MultiOLT_Tests.robot
@@ -130,6 +130,9 @@
     ...    REACHABLE    ${olt_serial_number}
     # Reboot the OLT using "voltctl device reboot" command
     Reboot Device    ${olt_device_id}
+    # Wait for the OLT to actually go down
+    Wait Until Keyword Succeeds    360s    5s    Validate OLT Device    ENABLED    UNKNOWN    UNREACHABLE
+    ...    ${olt_serial_number}
     # validate that the ONUs on the other OLTs are still functional
     Verify ping is successful for ONUs not on this OLT     ${num_all_onus}    ${olt_device_id}
     #Verify that ping fails for the ONUs where the OLT has been rebooted