From f135f37a502d99c9c9fcbfd8c9c972e66089071c Mon Sep 17 00:00:00 2001
From: Junchao-Mellanox <57339448+Junchao-Mellanox@users.noreply.github.com>
Date: Tue, 7 Jun 2022 20:13:16 +0800
Subject: [PATCH] [Mellanox] optimize platform API import time (#10815)

- Why I did it
"import sonic_platform" takes about 600ms ~ 1000ms, it is kind of slow. After this optimization, the time is about 100ms. The benefit is that those CLIs which does not need the slow import sentence would be faster than before.

- How I did it
Find slow import and call them when need.

- How to verify it
Measure the import time.
---
 .../mellanox/mlnx-platform-api/sonic_platform/chassis.py   | 7 ++++---
 .../mlnx-platform-api/sonic_platform/device_data.py        | 2 +-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/platform/mellanox/mlnx-platform-api/sonic_platform/chassis.py b/platform/mellanox/mlnx-platform-api/sonic_platform/chassis.py
index c7bafc0d8..f68d1033f 100644
--- a/platform/mellanox/mlnx-platform-api/sonic_platform/chassis.py
+++ b/platform/mellanox/mlnx-platform-api/sonic_platform/chassis.py
@@ -30,7 +30,6 @@ try:
 
     from . import utils
     from .device_data import DeviceDataManager
-    from .sfp import SFP, deinitialize_sdk_handle
 except ImportError as e:
     raise ImportError (str(e) + "- required module not found")
 
@@ -113,8 +112,10 @@ class Chassis(ChassisBase):
         if self.sfp_event:
             self.sfp_event.deinitialize()
 
-        if SFP.shared_sdk_handle:
-            deinitialize_sdk_handle(SFP.shared_sdk_handle)
+        if self._sfp_list:
+            from .sfp import SFP, deinitialize_sdk_handle
+            if SFP.shared_sdk_handle:
+                deinitialize_sdk_handle(SFP.shared_sdk_handle)
 
     ##############################################
     # PSU methods
diff --git a/platform/mellanox/mlnx-platform-api/sonic_platform/device_data.py b/platform/mellanox/mlnx-platform-api/sonic_platform/device_data.py
index cd909231d..17fe88037 100644
--- a/platform/mellanox/mlnx-platform-api/sonic_platform/device_data.py
+++ b/platform/mellanox/mlnx-platform-api/sonic_platform/device_data.py
@@ -17,7 +17,6 @@
 
 import glob
 import os
-from sonic_py_common import device_info
 
 from . import utils
 
@@ -173,6 +172,7 @@ class DeviceDataManager:
     @classmethod
     @utils.read_only_cache()
     def get_platform_name(cls):
+        from sonic_py_common import device_info
         return device_info.get_platform()
 
     @classmethod