[Mellanox] [201911] Fix issue: set fan led in certain order causes incorrect physical fan led color

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

@@ -13,6 +13,8 @@
 
 try:
     from sonic_platform_base.fan_base import FanBase
+
+    from .led import SharedLed, ComponentFaultyIndicator
     from .utils import read_int_from_file, read_str_from_file, write_file
 except ImportError as e:
     raise ImportError (str(e) + "- required module not found")
@@ -41,6 +43,10 @@ class Fan(FanBase):
     min_cooling_level = 2
     MIN_VALID_COOLING_LEVEL = 1
     MAX_VALID_COOLING_LEVEL = 10
+
+    # Fan drawer leds
+    fan_drawer_leds = {}
+
     # PSU fan speed vector
     PSU_FAN_SPEED = ['0x3c', '0x3c', '0x3c', '0x3c', '0x3c',
                      '0x3c', '0x3c', '0x46', '0x50', '0x5a', '0x64']
@@ -50,6 +56,14 @@ def __init__(self, has_fan_dir, fan_index, drawer_index = 1, psu_fan = False, pl
         self.index = fan_index + 1
         self.drawer_index = drawer_index + 1
 
+        if self.drawer_index not in Fan.fan_drawer_leds:
+            shared_led = SharedLed()
+            Fan.fan_drawer_leds[self.drawer_index] = shared_led
+        else:
+            shared_led = Fan.fan_drawer_leds[self.drawer_index]
+
+        self.fault_indicator = ComponentFaultyIndicator(shared_led)
+
         self.is_psu_fan = psu_fan
         self.always_presence = False if platform not in platform_with_unplugable_fan else True
 
@@ -250,6 +264,13 @@ def _get_led_capability(self):
         return cap_list
 
     def set_status_led(self, color):
+        if self.is_psu_fan:
+            return False
+        self.fault_indicator.set_status(color)
+        target_color = Fan.fan_drawer_leds[self.drawer_index].get_status()
+        return self._set_status_led(color)
+
+    def _set_status_led(self, color):
         """
         Set led to expected color
 
@@ -264,9 +285,6 @@ def set_status_led(self, color):
         if led_cap_list is None:
             return False
 
-        if self.is_psu_fan:
-            # PSU fan led status is not able to set
-            return False
         status = False
         try:
             if color == 'green':

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

@@ -0,0 +1,51 @@
+class Led(object):
+    STATUS_LED_COLOR_GREEN = 'green'
+    STATUS_LED_COLOR_GREEN_BLINK = 'green_blink'
+    STATUS_LED_COLOR_RED = 'red'
+    STATUS_LED_COLOR_RED_BLINK = 'red_blink'
+    STATUS_LED_COLOR_ORANGE = 'orange'
+    STATUS_LED_COLOR_ORANGE_BLINK = 'orange_blink'
+    STATUS_LED_COLOR_OFF = 'off'
+
+
+class SharedLed(object):
+    LED_PRIORITY = {
+        Led.STATUS_LED_COLOR_RED: 0,
+        Led.STATUS_LED_COLOR_GREEN: 1
+    }
+
+    def __init__(self):
+        self._virtual_leds = []
+        self._target_color = Led.STATUS_LED_COLOR_GREEN
+
+    def add_virtual_leds(self, led):
+        self._virtual_leds.append(led)
+
+    def update_status_led(self):
+        target_color = Led.STATUS_LED_COLOR_GREEN
+        for virtual_led in self._virtual_leds:
+            if SharedLed.LED_PRIORITY[virtual_led.get_led_color()] < SharedLed.LED_PRIORITY[target_color]:
+                target_color = virtual_led.get_led_color()
+
+        self._target_color = target_color
+        return True
+
+    def get_status(self):
+        return self._target_color
+
+
+class ComponentFaultyIndicator(object):
+    def __init__(self, shared_led):
+        self._color = Led.STATUS_LED_COLOR_GREEN
+        self._shared_led = shared_led
+        self._shared_led.add_virtual_leds(self)
+
+    def set_status(self, color):
+        self._color = color
+        return self._shared_led.update_status_led()
+
+    def get_led_color(self):
+        return self._color
+
+    def get_status(self):
+        return self._shared_led.get_status()