[Mellanox] [202106] Fix issue: SFP might not be re-initialized after cable plug in (#9387)

- Why I did it
Fix issue: SFP might not be re-initialized after cable plug in. There could be case like:
1. The SFP object was initialized as QSFP type
2. User use adapter to connect a SFP to a QSFP port
3. The SFP object treat the SFP as QSFP and failed to process EEPROM

- How I did it
If a new SFP is plugged, always re-initialize the SFP

- How to verify it
Added unit test case

platform/mellanox/mlnx-platform-api/sonic_platform/chassis.py

@@ -84,7 +84,7 @@ class Chassis(ChassisBase):
 
         # Initialize DMI data
         self.dmi_data = None
-        
+
         # move the initialization of each components to their dedicated initializer
         # which will be called from platform
         #
@@ -261,7 +261,7 @@ class Chassis(ChassisBase):
     def get_revision(self):
         """
         Retrieves the hardware revision of the device
-        
+
         Returns:
             string: Revision value of device
         """
@@ -269,7 +269,7 @@ class Chassis(ChassisBase):
             self.dmi_data = self._parse_dmi(DMI_FILE)
 
         return self.dmi_data.get(DMI_VERSION, "N/A")
-        
+
     ##############################################
     # SFP methods
     ##############################################
@@ -290,7 +290,7 @@ class Chassis(ChassisBase):
         Retrieves all sfps available on this chassis
 
         Returns:
-            A list of objects derived from SfpBase representing all sfps 
+            A list of objects derived from SfpBase representing all sfps
             available on this chassis
         """
         if not self.sfp_module_full_initialized:
@@ -361,7 +361,7 @@ class Chassis(ChassisBase):
         Note:
             We overload this method to ensure that watchdog is only initialized
             when it is referenced. Currently, only one daemon can open the watchdog.
-            To initialize watchdog in the constructor causes multiple daemon 
+            To initialize watchdog in the constructor causes multiple daemon
             try opening watchdog when loading and constructing a chassis object
             and fail. By doing so we can eliminate that risk.
         """
@@ -450,7 +450,7 @@ class Chassis(ChassisBase):
 
     def _verify_reboot_cause(self, filename):
         '''
-        Open and read the reboot cause file in 
+        Open and read the reboot cause file in
         /var/run/hwmanagement/system (which is defined as REBOOT_CAUSE_ROOT)
         If a reboot cause file doesn't exists, returns '0'.
         '''
@@ -550,7 +550,7 @@ class Chassis(ChassisBase):
                 - True if call successful, False if not;
                 - A nested dictionary where key is a device type,
                   value is a dictionary with key:value pairs in the format of
-                  {'device_id':'device_event'}, 
+                  {'device_id':'device_event'},
                   where device_id is the device ID for this device and
                         device_event,
                              status='1' represents device inserted,
@@ -594,10 +594,6 @@ class Chassis(ChassisBase):
         :param port_dict: SFP event data
         :return:
         """
-        # SFP not initialize yet, do nothing
-        if not self.sfp_module_full_initialized:
-            return
-
         from . import sfp
         for index, status in port_dict.items():
             if status == sfp.SFP_STATUS_INSERTED:

platform/mellanox/mlnx-platform-api/tests/test_sfp.py

@@ -1,7 +1,7 @@
 import os
 import sys
 import pytest
-from mock import MagicMock
+from mock import MagicMock, patch
 from .mock_platform import MockFan
 
 test_path = os.path.dirname(os.path.abspath(__file__))
@@ -11,7 +11,7 @@ sys.path.insert(0, modules_path)
 os.environ["PLATFORM_API_UNIT_TESTING"] = "1"
 
 from sonic_py_common import device_info
-from sonic_platform.sfp import SFP, SX_PORT_MODULE_STATUS_INITIALIZING, SX_PORT_MODULE_STATUS_PLUGGED, SX_PORT_MODULE_STATUS_UNPLUGGED, SX_PORT_MODULE_STATUS_PLUGGED_WITH_ERROR, SX_PORT_MODULE_STATUS_PLUGGED_DISABLED
+from sonic_platform.sfp import SFP, SX_PORT_MODULE_STATUS_INITIALIZING, SX_PORT_MODULE_STATUS_PLUGGED, SX_PORT_MODULE_STATUS_UNPLUGGED, SX_PORT_MODULE_STATUS_PLUGGED_WITH_ERROR, SX_PORT_MODULE_STATUS_PLUGGED_DISABLED, SFP_STATUS_INSERTED
 
 from sonic_platform.chassis import Chassis
 
@@ -123,3 +123,16 @@ def test_sfp_get_error_status():
         description = sfp.get_error_description()
 
         assert description == expected_description
+
+
+@patch('sonic_platform.sfp.SFP.reinit')
+def test_reinit_sfps(mock_reinit_sfps):
+    port_dict = {}
+    chassis = Chassis()
+    chassis.reinit_sfps(port_dict)
+    assert not mock_reinit_sfps.called
+
+    port_dict = {1: SFP_STATUS_INSERTED}
+    chassis.reinit_sfps(port_dict)
+    assert mock_reinit_sfps.called
+    assert chassis._sfp_list[0] is not None