[chassis][voq] broadcom-dnx does not support SAI_PORT_STAT_IN_DROPPED…

…_PKTS starting from SAI 11.x. (sonic-net#14743)

SAI thrift call sai_thrift_read_port_counters() reads a collection of counters together, including SAI_PORT_STAT_IN_DROPPED_PKTS. Starting from BRCM SAI 11.x, SAI_PORT_STAT_IN_DROPPED_PKTS is not supported and retrieving the count may fail SAI call sonic-net/sonic-buildimage#19998. In order to retrieve other counters correctly, read SAI_PORT_STAT_IN_DROPPED_PKTS in a separate SAI call.

tests/saitests/py3/switch.py

@@ -805,7 +805,14 @@ def sai_thrift_read_port_counters(client, asic_type, port):
     port_cnt_ids.append(SAI_PORT_STAT_PFC_7_TX_PKTS)
     port_cnt_ids.append(SAI_PORT_STAT_IF_OUT_OCTETS)
     port_cnt_ids.append(SAI_PORT_STAT_IF_OUT_UCAST_PKTS)
-    port_cnt_ids.append(SAI_PORT_STAT_IN_DROPPED_PKTS)
+
+    # broadcom-dnx does not support SAI_PORT_STAT_IN_DROPPED_PKTS. Reading this counter may fail
+    # to retrieve other counters (https://github.com/sonic-net/sonic-buildimage/issues/19998).
+    # Since we cannot tell if the ASIC is DNX or or not from provided asic_type, read the counter
+    # separately in another SAI call for all broadcom ASIC.
+    if asic_type != 'broadcom':
+        port_cnt_ids.append(SAI_PORT_STAT_IN_DROPPED_PKTS)
+
     port_cnt_ids.append(SAI_PORT_STAT_OUT_DROPPED_PKTS)
     port_cnt_ids.append(SAI_PORT_STAT_IF_IN_UCAST_PKTS)
     port_cnt_ids.append(SAI_PORT_STAT_IF_IN_NON_UCAST_PKTS)
@@ -819,6 +826,14 @@ def sai_thrift_read_port_counters(client, asic_type, port):
     if asic_type == 'mellanox':
         counters_results.append(0)
 
+    # Read SAI_PORT_STAT_IN_DROPPED_PKTS now and insert the cnt at the correct
+    # index in the counter results.
+    if asic_type == 'broadcom':
+        in_drop_pkts_cnt_id = [SAI_PORT_STAT_IN_DROPPED_PKTS]
+        in_drop_pkts_cnt_result = client.sai_thrift_get_port_stats(
+            port, in_drop_pkts_cnt_id, 1)
+        counters_results.insert(12, in_drop_pkts_cnt_result[0])
+
     queue_list = []
     port_attr_list = client.sai_thrift_get_port_attribute(port)
     attr_list = port_attr_list.attr_list