component/bt: add simple ADV flow control mechanism -- drop the packets when the adv report queues are considered full

components/bt/host/bluedroid/btc/profile/std/gap/btc_gap_ble.c

@@ -51,6 +51,8 @@ static uint16_t btc_adv_list_count = 0;
 #endif
 
 #define BTC_GAP_BLE_ADV_RPT_QUEUE_IDX            (1)
+#define BTC_GAP_BLE_ADV_RPT_BATCH_SIZE           (10)
+#define BTC_GAP_BLE_ADV_RPT_QUEUE_LEN_MAX        (200)
 
 #if (BLE_42_FEATURE_SUPPORT == TRUE)
 typedef struct {
@@ -565,6 +567,9 @@ static void btc_gap_ble_adv_pkt_handler(void *arg)
 {
     btc_gap_ble_env_t *p_env = &btc_gap_ble_env;
     size_t pkts_to_process = pkt_queue_length(p_env->adv_rpt_queue);
+    if (pkts_to_process > BTC_GAP_BLE_ADV_RPT_BATCH_SIZE) {
+        pkts_to_process = BTC_GAP_BLE_ADV_RPT_BATCH_SIZE;
+    }
 
     for (size_t i = 0; i < pkts_to_process; i++) {
         pkt_linked_item_t *linked_pkt = pkt_queue_dequeue(p_env->adv_rpt_queue);
@@ -596,6 +601,12 @@ static void btc_process_adv_rpt_pkt(tBTA_DM_SEARCH_EVT event, tBTA_DM_SEARCH *p_
     btc_adv_list_count ++;
 #endif
 
+    // drop ADV packets if data queue length goes above threshold
+    btc_gap_ble_env_t *p_env = &btc_gap_ble_env;
+    if (pkt_queue_length(p_env->adv_rpt_queue) >= BTC_GAP_BLE_ADV_RPT_QUEUE_LEN_MAX) {
+        return;
+    }
+
     pkt_linked_item_t *linked_pkt = osi_calloc(BT_PKT_LINKED_HDR_SIZE + sizeof(esp_ble_gap_cb_param_t));
     if (linked_pkt == NULL) {
         return;
@@ -617,7 +628,6 @@ static void btc_process_adv_rpt_pkt(tBTA_DM_SEARCH_EVT event, tBTA_DM_SEARCH *p_
         memcpy(scan_rst->ble_adv, p_data->inq_res.p_eir, sizeof(scan_rst->ble_adv));
     } while (0);
 
-    btc_gap_ble_env_t *p_env = &btc_gap_ble_env;
     pkt_queue_enqueue(p_env->adv_rpt_queue, linked_pkt);
     osi_thread_post_event(p_env->adv_rpt_ready, OSI_THREAD_MAX_TIMEOUT);
 }

components/bt/host/bluedroid/hci/hci_hal_h4.c

@@ -40,6 +40,7 @@
 #define PACKET_TYPE_TO_INBOUND_INDEX(type) ((type) - 2)
 #define PACKET_TYPE_TO_INDEX(type) ((type) - 1)
 #define HCI_UPSTREAM_DATA_QUEUE_IDX   (1)
+#define HCI_HAL_BLE_ADV_RPT_QUEUE_LEN_MAX      (200)
 
 extern bool BTU_check_queue_is_congest(void);
 
@@ -407,6 +408,12 @@ static int host_recv_pkt_cb(uint8_t *data, uint16_t len)
         memcpy(pkt->data, data, len);
         fixed_queue_enqueue(hci_hal_env.rx_q, pkt, FIXED_QUEUE_MAX_TIMEOUT);
     } else {
+#if !BLE_ADV_REPORT_FLOW_CONTROL
+        // drop the packets if pkt_queue length goes beyond upper limit
+        if (pkt_queue_length(hci_hal_env.adv_rpt_q) > HCI_HAL_BLE_ADV_RPT_QUEUE_LEN_MAX) {
+            return 0;
+        }
+#endif
         pkt_size = BT_PKT_LINKED_HDR_SIZE + BT_HDR_SIZE + len;
         linked_pkt = (pkt_linked_item_t *) osi_calloc(pkt_size);
         if (!linked_pkt) {

components/bt/host/bluedroid/stack/btm/btm_ble_gap.c

@@ -57,6 +57,8 @@
 #define MIN_ADV_LENGTH                       2
 #define BTM_VSC_CHIP_CAPABILITY_RSP_LEN_L_RELEASE 9
 
+#define BTM_BLE_GAP_ADV_RPT_BATCH_SIZE           (10)
+
 #if BTM_DYNAMIC_MEMORY == FALSE
 static tBTM_BLE_VSC_CB cmn_ble_gap_vsc_cb;
 #else
@@ -3463,6 +3465,9 @@ static void btm_adv_pkt_handler(void *arg)
 
     tBTM_BLE_CB *p_cb = &btm_cb.ble_ctr_cb;
     size_t pkts_to_process = pkt_queue_length(p_cb->adv_rpt_queue);
+    if (pkts_to_process > BTM_BLE_GAP_ADV_RPT_BATCH_SIZE) {
+        pkts_to_process = BTM_BLE_GAP_ADV_RPT_BATCH_SIZE;
+    }
 
     for (size_t i = 0; i < pkts_to_process; i++) {
         pkt_linked_item_t *linked_pkt = pkt_queue_dequeue(p_cb->adv_rpt_queue);