Fix test issues in the dpu platform test (#19181)

1. Need a post check after restarting pmon, otherwise the pmon could not fully started and it will fail the next case.
2. Need to restore the DPU admin on status if the check after shutdown DPUs fails.

Change-Id: I80538d3a66b9c5c7d590f51d7c6703f62e982fe4

Author: congh-nvidia

tests/smartswitch/platform_tests/test_platform_dpu.py

@@ -105,13 +105,14 @@ def test_pcie_link(duthosts, dpuhosts,
     dpus_shutdown_and_check(duthost, dpu_on_list, num_dpu_modules)
 
     output_pcie_info = duthost.command(CMD_PCIE_INFO)["stdout_lines"]
-    pytest_assert(output_pcie_info[-1] ==
-                  'PCIe Device Checking All Test ----------->>> PASSED',
-                  "PCIe Link test failed'{}'".format(duthost.hostname))
-
-    for index in range(len(dpu_on_list)):
-        duthost.shell("sudo config chassis modules \
-                       startup %s" % (dpu_on_list[index]))
+    try:
+        pytest_assert(output_pcie_info[-1] ==
+                      'PCIe Device Checking All Test ----------->>> PASSED',
+                      "PCIe Link test failed'{}'".format(duthost.hostname))
+    finally:
+        for index in range(len(dpu_on_list)):
+            duthost.shell("sudo config chassis modules \
+                           startup %s" % (dpu_on_list[index]))
 
     post_test_dpus_check(duthost, dpuhosts, dpu_on_list, ip_address_list, num_dpu_modules, "Non-Hardware")
 
@@ -123,28 +124,23 @@ def test_pcie_link(duthosts, dpuhosts,
                   "PCIe Link test failed'{}'".format(duthost.hostname))
 
 
-def test_restart_pmon(duthosts, enum_rand_one_per_hwsku_hostname,
+def test_restart_pmon(duthosts, dpuhosts, enum_rand_one_per_hwsku_hostname,
                       platform_api_conn, num_dpu_modules):  # noqa: F811
     """
     @summary: Verify `DPU status and pcie Link after restart pmon`
     """
     duthost = duthosts[enum_rand_one_per_hwsku_hostname]
     ip_address_list = []
 
+    ip_address_list, dpu_on_list, dpu_off_list = pre_test_check(
+                                                 duthost,
+                                                 platform_api_conn,
+                                                 num_dpu_modules)
+
     logging.info("Checking pmon status")
     pmon_status = check_pmon_status(duthost)
     pytest_assert(pmon_status == 1, "PMON status is Not UP")
 
-    for index in range(num_dpu_modules):
-        dpu_name = module.get_name(platform_api_conn, index)
-        rc = check_dpu_module_status(duthost, "on", dpu_name)
-        if rc:
-            ip_address_list.append(
-                          module.get_midplane_ip(platform_api_conn, index))
-
-    ping_status = check_dpu_ping_status(duthost, ip_address_list)
-    pytest_assert(ping_status == 1, "Ping to one or more DPUs has failed")
-
     logging.info("Restarting pmon....")
     duthost.shell("systemctl restart pmon")
 
@@ -155,6 +151,8 @@ def test_restart_pmon(duthosts, enum_rand_one_per_hwsku_hostname,
     pmon_status = check_pmon_status(duthost)
     pytest_assert(pmon_status == 1, "PMON status is Not UP")
 
+    post_test_dpus_check(duthost, dpuhosts, dpu_on_list, ip_address_list, num_dpu_modules, "Non-Hardware")
+
 
 def test_system_health_state(duthosts, enum_rand_one_per_hwsku_hostname,
                              platform_api_conn, num_dpu_modules):  # noqa: F811
@@ -170,9 +168,14 @@ def test_system_health_state(duthosts, enum_rand_one_per_hwsku_hostname,
     logging.info("Shutting DOWN the DPUs in parallel")
     dpus_shutdown_and_check(duthost, dpu_on_list, num_dpu_modules)
 
-    for index in range(len(dpu_on_list)):
-        check_dpu_health_status(duthost, dpu_on_list[index],
-                                'Offline', 'down')
+    try:
+        for index in range(len(dpu_on_list)):
+            check_dpu_health_status(duthost, dpu_on_list[index],
+                                    'Offline', 'down')
+    finally:
+        for index in range(len(dpu_on_list)):
+            duthost.shell("sudo config chassis modules \
+                           startup %s" % (dpu_on_list[index]))
 
     logging.info("Starting UP the DPUs in parallel")
     dpus_startup_and_check(duthost, dpu_on_list, num_dpu_modules)