[Mellanox] clear fan from chassis._fan_list (#7682)

#### Why I did it

According to thermalctld hld, each fan must belong to a fan drawer, if the fan drawer does not physically exist, put fan into a virtual fan drawer. This PR is to clear fan from chassis._fan_list

#### How I did it

1. Don't put fan to chassis._fan_list
2. Always query fan from fan_drawer

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

@@ -160,7 +160,6 @@ class Chassis(ChassisBase):
                 fan = Fan(fan_index, drawer, index + 1)
                 fan_index += 1
                 drawer._fan_list.append(fan)
-                self._fan_list.append(fan)
 
 
     def initialize_single_sfp(self, index):

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

@@ -24,26 +24,27 @@ class FanInfo(ThermalPolicyInfoBase):
         :return:
         """
         self._status_changed = False
-        for fan in chassis.get_all_fans():
+        for fan_drawer in chassis.get_all_fan_drawers():
-            presence = fan.get_presence()
+            for fan in fan_drawer.get_all_fans():
-            status = fan.get_status()
+                presence = fan.get_presence()
-            if presence and fan not in self._presence_fans:
+                status = fan.get_status()
-                self._presence_fans.add(fan)
+                if presence and fan not in self._presence_fans:
-                self._status_changed = True
+                    self._presence_fans.add(fan)
-                if fan in self._absence_fans:
+                    self._status_changed = True
-                    self._absence_fans.remove(fan)
+                    if fan in self._absence_fans:
-            elif not presence and fan not in self._absence_fans:
+                        self._absence_fans.remove(fan)
-                self._absence_fans.add(fan)
+                elif not presence and fan not in self._absence_fans:
-                self._status_changed = True
+                    self._absence_fans.add(fan)
-                if fan in self._presence_fans:
+                    self._status_changed = True
-                    self._presence_fans.remove(fan)
+                    if fan in self._presence_fans:
+                        self._presence_fans.remove(fan)
 
-            if not status and fan not in self._fault_fans:
+                if not status and fan not in self._fault_fans:
-                self._fault_fans.add(fan)
+                    self._fault_fans.add(fan)
-                self._status_changed = True
+                    self._status_changed = True
-            elif status and fan in self._fault_fans:
+                elif status and fan in self._fault_fans:
-                self._fault_fans.remove(fan)
+                    self._fault_fans.remove(fan)
-                self._status_changed = True
+                    self._status_changed = True
                     
 
     def get_absence_fans(self):

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

@@ -36,10 +36,19 @@ class MockPsu:
         return []
 
 
+class MockFanDrawer:
+    def __init__(self):
+        self.fan_list = []
+
+    def get_all_fans(self):
+        return self.fan_list
+
+
 class MockChassis:
     def __init__(self):
         self.fan_list = []
         self.psu_list = []
+        self.fan_drawer_list = []
 
     def get_all_psus(self):
         return self.psu_list
@@ -47,6 +56,9 @@ class MockChassis:
     def get_all_fans(self):
         return self.fan_list
 
+    def get_all_fan_drawers(self):
+        return self.fan_drawer_list
+
     def get_thermal_manager(self):
         from sonic_platform.thermal_manager import ThermalManager
         return ThermalManager
@@ -54,7 +66,9 @@ class MockChassis:
     def make_fan_absence(self):
         fan = MockFan()
         fan.presence = False
-        self.fan_list.append(fan)
+        fan_drawer = MockFanDrawer()
+        self.fan_drawer_list.append(fan_drawer)
+        fan_drawer.fan_list.append(fan)
 
     def make_psu_absence(self):
         psu = MockPsu()

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

@@ -3,7 +3,7 @@ import sys
 import pytest
 import json
 from mock import MagicMock
-from .mock_platform import MockChassis, MockFan, MockPsu
+from .mock_platform import MockChassis, MockFan, MockFanDrawer, MockPsu
 
 test_path = os.path.dirname(os.path.abspath(__file__))
 modules_path = os.path.dirname(test_path)
@@ -49,15 +49,14 @@ def test_fan_info():
     assert len(fan_info.get_fault_fans()) == 0
     assert fan_info.is_status_changed()
 
-    fan_list = chassis.get_all_fans()
+    chassis.get_all_fan_drawers()[0].get_all_fans()[0].presence = True
-    fan_list[0].presence = True
     fan_info.collect(chassis)
     assert len(fan_info.get_absence_fans()) == 0
     assert len(fan_info.get_presence_fans()) == 1
     assert len(fan_info.get_fault_fans()) == 0
     assert fan_info.is_status_changed()
 
-    fan_list[0].status = False
+    chassis.get_all_fan_drawers()[0].get_all_fans()[0].status = False
     fan_info.collect(chassis)
     assert len(fan_info.get_absence_fans()) == 0
     assert len(fan_info.get_presence_fans()) == 1
@@ -90,10 +89,10 @@ def test_psu_info():
 def test_fan_policy(thermal_manager):
     chassis = MockChassis()
     chassis.make_fan_absence()
-    chassis.fan_list.append(MockFan())
+    chassis.get_all_fan_drawers()[0].get_all_fans().append(MockFan())
     thermal_manager.run_policy(chassis)
 
-    fan_list = chassis.get_all_fans()
+    fan_list = chassis.get_all_fan_drawers()[0].get_all_fans()
     assert fan_list[1].speed == 100
     Thermal.set_thermal_algorithm_status.assert_called_with(False, False)
 
@@ -144,7 +143,7 @@ def test_any_fan_absence_condition():
     condition = AnyFanAbsenceCondition()
     assert condition.is_match({'fan_info': fan_info})
 
-    fan = chassis.get_all_fans()[0]
+    fan = chassis.get_all_fan_drawers()[0].get_all_fans()[0]
     fan.presence = True
     fan_info.collect(chassis)
     assert not condition.is_match({'fan_info': fan_info})
@@ -154,7 +153,7 @@ def test_all_fan_absence_condition():
     chassis = MockChassis()
     chassis.make_fan_absence()
     fan = MockFan()
-    fan_list = chassis.get_all_fans()
+    fan_list = chassis.get_all_fan_drawers()[0].get_all_fans()
     fan_list.append(fan)
     fan_info = FanInfo()
     fan_info.collect(chassis)
@@ -172,7 +171,7 @@ def test_all_fan_presence_condition():
     chassis = MockChassis()
     chassis.make_fan_absence()
     fan = MockFan()
-    fan_list = chassis.get_all_fans()
+    fan_list = chassis.get_all_fan_drawers()[0].get_all_fans()
     fan_list.append(fan)
     fan_info = FanInfo()
     fan_info.collect(chassis)
@@ -187,8 +186,9 @@ def test_all_fan_presence_condition():
 
 def test_any_fan_fault_condition():
     chassis = MockChassis()
+    chassis.get_all_fan_drawers().append(MockFanDrawer())
     fan = MockFan()
-    fan_list = chassis.get_all_fans()
+    fan_list = chassis.get_all_fan_drawers()[0].get_all_fans()
     fan_list.append(fan)
     fault_fan = MockFan()
     fault_fan.status = False
@@ -206,8 +206,9 @@ def test_any_fan_fault_condition():
 
 def test_all_fan_good_condition():
     chassis = MockChassis()
+    chassis.get_all_fan_drawers().append(MockFanDrawer())
     fan = MockFan()
-    fan_list = chassis.get_all_fans()
+    fan_list = chassis.get_all_fan_drawers()[0].get_all_fans()
     fan_list.append(fan)
     fault_fan = MockFan()
     fault_fan.status = False
@@ -302,7 +303,8 @@ def test_load_set_fan_speed_action():
 
 def test_execute_set_fan_speed_action():
     chassis = MockChassis()
-    fan_list = chassis.get_all_fans()
+    chassis.get_all_fan_drawers().append(MockFanDrawer())
+    fan_list = chassis.get_all_fan_drawers()[0].get_all_fans()
     fan_list.append(MockFan())
     fan_list.append(MockFan())
     fan_info = FanInfo()
@@ -364,7 +366,8 @@ def test_load_check_and_set_speed_action():
 
 def test_execute_check_and_set_fan_speed_action():
     chassis = MockChassis()
-    fan_list = chassis.get_all_fans()
+    chassis.get_all_fan_drawers().append(MockFanDrawer())
+    fan_list = chassis.get_all_fan_drawers()[0].get_all_fans()
     fan_list.append(MockFan())
     fan_list.append(MockFan())
     fan_info = FanInfo()