Skip CDB and VDM for flat memory modules (sonic-net#281)

* Skip CDB and VDM for flat memory modules

* Improve code coverage

* Fix test failure

* Fix test failure

* Fix test failure

sonic_platform_base/sonic_xcvr/api/public/cmis.py

@@ -27,8 +27,8 @@ class CmisApi(XcvrApi):
 
     def __init__(self, xcvr_eeprom):
         super(CmisApi, self).__init__(xcvr_eeprom)
-        self.vdm = CmisVdmApi(xcvr_eeprom)
-        self.cdb = CmisCdbApi(xcvr_eeprom)
+        self.vdm = CmisVdmApi(xcvr_eeprom) if not self.is_flat_memory() else None
+        self.cdb = CmisCdbApi(xcvr_eeprom) if not self.is_flat_memory() else None
 
     def get_model(self):
         '''
@@ -1015,7 +1015,7 @@ def get_vdm(self):
         '''
         This function returns all the VDM items, including real time monitor value, threholds and flags
         '''
-        vdm = self.vdm.get_vdm_allpage() if not self.is_flat_memory() else {}
+        vdm = self.vdm.get_vdm_allpage() if self.vdm is not None else {}
         return vdm
 
     def get_module_firmware_fault_state_changed(self):
@@ -1116,6 +1116,9 @@ def get_module_fw_mgmt_feature(self, verbose = False):
         the following upgrade with depend on these parameters.
         """
         txt = ''
+        if self.cdb is None:
+            return {'status': False, 'info': "CDB Not supported", 'result': None}
+
         # get fw upgrade features (CMD 0041h)
         starttime = time.time()
         autopaging = self.xcvr_eeprom.read(consts.AUTO_PAGING_SUPPORT)
@@ -1166,6 +1169,10 @@ def get_module_fw_info(self):
         Validity Status: 1 = invalid, 0 = valid
         """
         txt = ''
+
+        if self.cdb is None:
+            return {'status': False, 'info': "CDB Not supported", 'result': None}
+
         # get fw info (CMD 0100h)
         rpllen, rpl_chkcode, rpl = self.cdb.get_fw_info()
         # password issue
@@ -1250,6 +1257,8 @@ def module_fw_run(self, mode = 0x01):
         """
         # run module FW (CMD 0109h)
         txt = ''
+        if self.cdb is None:
+            return False, "CDB NOT supported on this module"
         starttime = time.time()
         fw_run_status = self.cdb.run_fw_image(mode)
         if fw_run_status == 1:
@@ -1280,6 +1289,8 @@ def module_fw_commit(self):
         Otherwise it will return False.
         """
         txt = ''
+        if self.cdb is None:
+            return False, "CDB NOT supported on this module"
         # commit module FW (CMD 010Ah)
         starttime = time.time()
         fw_commit_status= self.cdb.commit_fw_image()
@@ -1337,6 +1348,9 @@ def module_fw_download(self, startLPLsize, maxblocksize, lplonly_flag, autopagin
         This function returns True if download successfully completes. Otherwise it will return False where it fails.
         """
         txt = ''
+        if self.cdb is None:
+            return False, "CDB NOT supported on this module"
+
         # start fw download (CMD 0101h)
         starttime = time.time()
         try:

tests/sonic_xcvr/test_cmisCDB.py

@@ -1,5 +1,6 @@
 from mock import MagicMock
 import pytest
+from sonic_platform_base.sonic_xcvr.api.public.cmis import CmisApi
 from sonic_platform_base.sonic_xcvr.api.public.cmisCDB import CmisCdbApi
 from sonic_platform_base.sonic_xcvr.mem_maps.public.cmis import CmisMemMap
 from sonic_platform_base.sonic_xcvr.xcvr_eeprom import XcvrEeprom
@@ -13,6 +14,18 @@ class TestCDB(object):
     eeprom = XcvrEeprom(reader, writer, mem_map)
     api = CmisCdbApi(eeprom)
 
+    def test_cdb_is_none(self):
+        api = CmisApi(self.eeprom)
+        api.cdb = None
+        print(api)
+        print(api.get_module_fw_mgmt_feature())
+        assert False == api.get_module_fw_mgmt_feature()['status']
+        assert False == api.get_module_fw_info()['status']
+        assert False == api.module_fw_run()[0]
+        assert False == api.module_fw_commit()[0]
+        assert False == api.module_fw_download(None, None, None, None, None, None)[0]
+
+
     @pytest.mark.parametrize("mock_response, expected", [
         (64, False),
         (0, True)
@@ -101,7 +114,7 @@ def test_get_fw_management_features(self, mock_response, expected):
         self.api.cdb1_chkstatus = MagicMock()
         self.api.cdb1_chkstatus.return_value = mock_response[0]
         self.api.read_cdb = MagicMock()
-        self.api.read_cdb.return_value = mock_response[1]        
+        self.api.read_cdb.return_value = mock_response[1]
         result = self.api.get_fw_management_features()
         assert result == expected
 
@@ -185,7 +198,7 @@ def test_run_fw_image(self, mock_response, expected):
         self.api.cdb1_chkstatus.return_value = mock_response
         result = self.api.run_fw_image()
         assert result == expected
-        
+
     @pytest.mark.parametrize("mock_response, expected", [
         (1, 1),
         (64, 64),