enable and fortify ECN config GCU testing (#21236)

Author: dcaugher

tests/common/plugins/conditional_mark/tests_mark_conditions.yaml

@@ -2506,7 +2506,7 @@ generic_config_updater/test_ecn_config_update.py::test_ecn_config_updates:
     reason: "This test is not run on this asic type, topology, or version currently"
     conditions_logical_operator: "OR"
     conditions:
-      - "asic_type in ['cisco-8000']"
+      - "hwsku in ['Cisco-8800-LC-48H-C48']"
       - "topo_type in ['m0', 'mx', 'm1']"
       - "release in ['202211']"
 

tests/generic_config_updater/test_ecn_config_update.py

@@ -60,15 +60,16 @@ def get_asic_db_values(duthost, fields, cli_namespace_prefix):
     asic_db_values = {}
     for wred_object in wred_objects:
         oid = wred_object[wred_object.rfind(':') + 1:]
-        asic_db_values[oid] = {}
         wred_data = duthost.shell('sonic-db-cli {} ASIC_DB hgetall {}'
                                   .format(cli_namespace_prefix, wred_object))["stdout"]
         if "NULL" in wred_data:
             continue
         wred_data = ast.literal_eval(wred_data)
+        values = {}
         for field in fields:
-            value = int(wred_data[WRED_MAPPING[field]])
-            asic_db_values[oid][field] = value
+            values[field] = int(wred_data[WRED_MAPPING[field]])
+        if values:
+            asic_db_values[oid] = values
     return asic_db_values
 
 
@@ -137,8 +138,7 @@ def validate_wred_objects_in_asic_db():
 def get_wred_profiles(duthost, cli_namespace_prefix):
     wred_profiles = duthost.shell(f"sonic-db-cli {cli_namespace_prefix} CONFIG_DB keys \
                                   'WRED_PROFILE|*' | cut -d '|' -f 2")["stdout"]
-    wred_profiles = wred_profiles.split('\n')
-    return wred_profiles
+    return [w for w in wred_profiles.split('\n') if w]
 
 
 @pytest.mark.parametrize("configdb_field", ["green_min_threshold", "green_max_threshold", "green_drop_probability",
@@ -168,12 +168,14 @@ def test_ecn_config_updates(duthost, ensure_dut_readiness, configdb_field, opera
         for field in fields:
             value = int(ecn_data[field])
             if "probability" in field:
-                if 0 <= value <= 99:
+                if 0 <= value < 99:
                     value += 1
-                elif value == 100:
+                elif value >= 99:
                     value -= 1
                 else:
                     raise ValueError("Invalid probability value: {}".format(value))
+            elif "min" in field:
+                value -= 1
             else:
                 value += 1
             new_values[wred_profile][field] = value