[CMIS]Fix low-power to high power mode transition (sonic-net#268)

* [CMIS]Fix low-power to high power mode transition

* Remove python2 tests

* Improve code coverage

* Parametrize the test

* Improve code coverage

Author: prgeor

azure-pipelines.yml

@@ -46,9 +46,6 @@ steps:
 
 - script: |
     set -xe
-    sudo pip2 install swsssdk-2.0.1-py2-none-any.whl
-    sudo pip2 install sonic_py_common-1.0-py2-none-any.whl
-    sudo pip2 install sonic_config_engine-1.0-py2-none-any.whl
     sudo pip3 install swsssdk-2.0.1-py3-none-any.whl
     sudo pip3 install sonic_py_common-1.0-py3-none-any.whl
     sudo pip3 install sonic_yang_mgmt-1.0-py3-none-any.whl
@@ -66,31 +63,6 @@ steps:
     sudo apt-get install -y dotnet-sdk-5.0
   displayName: "Install .NET CORE"
 
-# Python 2
-- script: |
-    python2 setup.py test
-  displayName: 'Test Python 2'
-
-- task: PublishTestResults@2
-  inputs:
-    testResultsFiles: '$(System.DefaultWorkingDirectory)/test-results.xml'
-    testRunTitle: Python 2
-    failTaskOnFailedTests: true
-  condition: succeededOrFailed()
-  displayName: 'Publish Python 2 test results'
-
-- task: PublishCodeCoverageResults@1
-  inputs:
-    codeCoverageTool: Cobertura
-    summaryFileLocation: '$(System.DefaultWorkingDirectory)/coverage.xml'
-    reportDirectory: '$(System.DefaultWorkingDirectory)/htmlcov/'
-  displayName: 'Publish Python 2 test coverage'
-
-- script: |
-    set -e
-    python2 setup.py bdist_wheel
-  displayName: 'Build Python 2 wheel'
-
 # Python 3
 - script: |
     python3 setup.py test

sonic_platform_base/sonic_xcvr/api/public/cmis.py

@@ -22,6 +22,8 @@
 
 class CmisApi(XcvrApi):
     NUM_CHANNELS = 8
+    LowPwrRequestSW = 4
+    LowPwrAllowRequestHW = 6
 
     def __init__(self, xcvr_eeprom):
         super(CmisApi, self).__init__(xcvr_eeprom)
@@ -930,19 +932,20 @@ def set_lpmode(self, lpmode):
         lpmode_val = self.xcvr_eeprom.read(consts.MODULE_LEVEL_CONTROL)
         if lpmode_val is not None:
             if lpmode is True:
-                lpmode_val = lpmode_val | (1 << 4)
+                # Force module transition to LowPwr under SW control
+                lpmode_val = lpmode_val | (1 << CmisApi.LowPwrRequestSW)
                 self.xcvr_eeprom.write(consts.MODULE_LEVEL_CONTROL, lpmode_val)
                 time.sleep(0.1)
                 return self.get_lpmode()
             else:
-                lpmode_val = lpmode_val & ~(1 << 4)
+                # Force transition from LowPwr to HighPower state under SW control.
+                # This will transition LowPwrS signal to False. (see Table 6-12 CMIS v5.0)
+                lpmode_val = lpmode_val & ~(1 << CmisApi.LowPwrRequestSW)
+                lpmode_val = lpmode_val & ~(1 << CmisApi.LowPwrAllowRequestHW)
                 self.xcvr_eeprom.write(consts.MODULE_LEVEL_CONTROL, lpmode_val)
                 time.sleep(1)
-                lpmode = self.xcvr_eeprom.read(consts.TRANS_MODULE_STATUS_FIELD)
-                if lpmode is not None:
-                    if lpmode.get('ModuleState') == 'ModuleReady':
-                        return True
-                return False
+                mstate = self.get_module_state()
+                return True if mstate == 'ModuleReady' else False
         return False
 
     def get_loopback_capability(self):