[Mellanox] Skip the leftover hardware reboot cause in case of last boot is warm/fast reboot (#13246) (#13570)

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

@@ -30,6 +30,7 @@ try:
     from .utils import extract_RJ45_ports_index
     from . import utils
     from .device_data import DeviceDataManager
+    import re
 except ImportError as e:
     raise ImportError (str(e) + "- required module not found")
 
@@ -61,6 +62,10 @@ REBOOT_CAUSE_ROOT = HWMGMT_SYSTEM_ROOT
 
 REBOOT_CAUSE_FILE_LENGTH = 1
 
+REBOOT_TYPE_KEXEC_FILE = "/proc/cmdline"
+REBOOT_TYPE_KEXEC_PATTERN_WARM = ".*SONIC_BOOT_TYPE=(warm|fastfast).*"
+REBOOT_TYPE_KEXEC_PATTERN_FAST = ".*SONIC_BOOT_TYPE=(fast|fast-reboot).*"
+
 # Global logger class instance
 logger = Logger()
 
@@ -736,6 +741,18 @@ class Chassis(ChassisBase):
         self.reboot_by_software = 'reset_sw_reset'
         self.reboot_cause_initialized = True
 
+    def _parse_warmfast_reboot_from_proc_cmdline(self):
+        if os.path.isfile(REBOOT_TYPE_KEXEC_FILE):
+            with open(REBOOT_TYPE_KEXEC_FILE) as cause_file:
+                cause_file_kexec = cause_file.readline()
+            m = re.search(REBOOT_TYPE_KEXEC_PATTERN_WARM, cause_file_kexec)
+            if m and m.group(1):
+                return 'warm-reboot'
+            m = re.search(REBOOT_TYPE_KEXEC_PATTERN_FAST, cause_file_kexec)
+            if m and m.group(1):
+                return 'fast-reboot'
+        return None
+
     def get_reboot_cause(self):
         """
         Retrieves the cause of the previous reboot
@@ -748,6 +765,14 @@ class Chassis(ChassisBase):
             to pass a description of the reboot cause.
         """
         #read reboot causes files in the following order
+
+        # To avoid the leftover hardware reboot cause confusing the reboot cause determine service
+        # Skip the hardware reboot cause check if warm/fast reboot cause found from cmdline
+        if utils.is_host():
+            reboot_cause = self._parse_warmfast_reboot_from_proc_cmdline()
+            if reboot_cause:
+                return self.REBOOT_CAUSE_NON_HARDWARE, ''
+
         if not self.reboot_cause_initialized:
             self.initialize_reboot_cause()
 

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

@@ -224,6 +224,35 @@ class TestChassis:
             assert minor == value
             mock_file_content[file_path] = 0
 
+        utils.is_host = mock.MagicMock(return_value=True)
+        chassis._parse_warmfast_reboot_from_proc_cmdline = mock.MagicMock(return_value='warm-reboot')
+        for key, value in chassis.reboot_major_cause_dict.items():
+            file_path = os.path.join(REBOOT_CAUSE_ROOT, key)
+            mock_file_content[file_path] = 1
+            major, minor = chassis.get_reboot_cause()
+            assert major == chassis.REBOOT_CAUSE_NON_HARDWARE
+            assert minor == ''
+            mock_file_content[file_path] = 0
+
+        for key, value in chassis.reboot_minor_cause_dict.items():
+            file_path = os.path.join(REBOOT_CAUSE_ROOT, key)
+            mock_file_content[file_path] = 1
+            major, minor = chassis.get_reboot_cause()
+            assert major == chassis.REBOOT_CAUSE_NON_HARDWARE
+            assert minor == value
+            mock_file_content[file_path] = 0
+
+    def test_parse_warmfast_reboot_from_proc_cmdline(self):
+        chassis = Chassis()
+        with mock.patch("builtins.open", mock.mock_open(read_data="SONIC_BOOT_TYPE=warm")):
+            assert chassis._parse_warmfast_reboot_from_proc_cmdline() == "warm-reboot"
+
+        with mock.patch("builtins.open", mock.mock_open(read_data="SONIC_BOOT_TYPE=fast")):
+            assert chassis._parse_warmfast_reboot_from_proc_cmdline() == "fast-reboot"
+
+        with mock.patch("builtins.open", mock.mock_open(read_data="SONIC_BOOT_TYPE=None")):
+            assert chassis._parse_warmfast_reboot_from_proc_cmdline() == None
+
     def test_module(self):
         from sonic_platform.chassis import ModularChassis
         # Test get_num_modules, it should not create any SFP objects