bluedroid: configurable max gattc cache characteristic count

components/bt/host/bluedroid/Kconfig.in

@@ -215,6 +215,14 @@ config BT_GATTC_ENABLE
     help
         This option can be close when the app work only on gatt server mode
 
+config BT_GATTC_MAX_CACHE_CHAR
+    int "Max gattc cache characteristic for discover"
+    depends on BT_GATTC_ENABLE
+    range 1 500
+    default 40
+    help
+        Maximum GATTC cache characteristic count
+
 config BT_GATTC_CACHE_NVS_FLASH
     bool "Save gattc cache data to nvs flash"
     depends on BT_GATTC_ENABLE

components/bt/host/bluedroid/api/esp_gatts_api.c

@@ -94,7 +94,7 @@ esp_err_t esp_ble_gatts_create_attr_tab(const esp_gatts_attr_db_t *gatts_attr_db
     ESP_BLUEDROID_STATUS_CHECK(ESP_BLUEDROID_STATUS_ENABLED);
 
     if (max_nb_attr > ESP_GATT_ATTR_HANDLE_MAX) {
-        LOG_ERROR("%s the number of attribute should not be greater than CONFIG_BT_GATT_MAX_SR_ATTRIBUTES\n");
+        LOG_ERROR("The number of attribute should not be greater than CONFIG_BT_GATT_MAX_SR_ATTRIBUTES\n");
         return ESP_ERR_INVALID_ARG;
     }
 

components/bt/host/bluedroid/bta/gatt/bta_gattc_cache.c

@@ -541,7 +541,6 @@ void bta_gattc_start_disc_char_dscp(UINT16 conn_id, tBTA_GATTC_SERV *p_srvc_cb)
     if (bta_gattc_discover_procedure(conn_id, p_srvc_cb, GATT_DISC_CHAR_DSCPT) != 0) {
         bta_gattc_char_dscpt_disc_cmpl(conn_id, p_srvc_cb);
     }
-
 }
 
 void bta_gattc_update_include_service(const list_t *services) {
@@ -693,7 +692,9 @@ static void bta_gattc_char_dscpt_disc_cmpl(UINT16 conn_id, tBTA_GATTC_SERV *p_sr
 {
     tBTA_GATTC_ATTR_REC *p_rec = NULL;
 
-    if (--p_srvc_cb->total_char > 0) {
+    /* Recursive function will cause BTU stack overflow when there are a large number of characteristic
+     * without descriptor to discover. So replace it with while function */
+    while (--p_srvc_cb->total_char > 0) {
         p_rec = p_srvc_cb->p_srvc_list + (++ p_srvc_cb->cur_char_idx);
         /* add the next characteristic into cache */
         bta_gattc_add_char_to_cache (p_srvc_cb,
@@ -701,11 +702,14 @@ static void bta_gattc_char_dscpt_disc_cmpl(UINT16 conn_id, tBTA_GATTC_SERV *p_sr
                                      p_rec->s_handle,
                                      &p_rec->uuid,
                                      p_rec->property);
+        /* start to discover next characteristic for descriptor */
+        if (bta_gattc_discover_procedure(conn_id, p_srvc_cb, GATT_DISC_CHAR_DSCPT) == 0) {
+            /* send att req and wait for att rsp */
+            break;
+        }
+    }
 
-        /* start discoverying next characteristic for char descriptor */
+    if (p_srvc_cb->total_char == 0) /* all characteristic has been explored, start with next service if any */
-        bta_gattc_start_disc_char_dscp(conn_id, p_srvc_cb);
-    } else
-        /* all characteristic has been explored, start with next service if any */
     {
 #if (defined BTA_GATT_DEBUG && BTA_GATT_DEBUG == TRUE)
         APPL_TRACE_ERROR("all char has been explored");
@@ -772,7 +776,7 @@ static tBTA_GATT_STATUS bta_gattc_add_srvc_to_list(tBTA_GATTC_SERV *p_srvc_cb,
         /* allocate bigger buffer ?? */
         status = GATT_DB_FULL;
 
-        APPL_TRACE_ERROR("service not added, no resources or wrong state");
+        APPL_TRACE_ERROR("service not added, no resources or wrong state, see CONFIG_BT_GATTC_MAX_CACHE_CHAR");
     }
     return status;
 }
@@ -814,7 +818,7 @@ static tBTA_GATT_STATUS bta_gattc_add_char_to_list(tBTA_GATTC_SERV *p_srvc_cb,
         }
         p_srvc_cb->next_avail_idx ++;
     } else {
-        APPL_TRACE_ERROR("char not added, no resources");
+        APPL_TRACE_ERROR("char not added, no resources, see CONFIG_BT_GATTC_MAX_CACHE_CHAR");
         /* allocate bigger buffer ?? */
         status = BTA_GATT_DB_FULL;
     }

components/bt/host/bluedroid/bta/gatt/include/bta_gattc_int.h

@@ -270,7 +270,6 @@ typedef struct {
 } tBTA_GATTC_ATTR_REC;
 
 
-#define BTA_GATTC_MAX_CACHE_CHAR    40
 #define BTA_GATTC_ATTR_LIST_SIZE    (BTA_GATTC_MAX_CACHE_CHAR * sizeof(tBTA_GATTC_ATTR_REC))
 
 #ifndef BTA_GATTC_CACHE_SRVR_SIZE
@@ -305,10 +304,10 @@ typedef struct {
 
     tBTA_GATTC_ATTR_REC *p_srvc_list;
     UINT8               cur_srvc_idx;
-    UINT8               cur_char_idx;
+    UINT16               cur_char_idx;
-    UINT8               next_avail_idx;
+    UINT16               next_avail_idx;
     UINT8               total_srvc;
-    UINT8               total_char;
+    UINT16               total_char;
     UINT16              total_attr;
     UINT8               srvc_hdl_chg;   /* service handle change indication pending */
     UINT16              attr_index;     /* cahce NV saving/loading attribute index */

components/bt/host/bluedroid/common/include/common/bluedroid_user_config.h

@@ -134,6 +134,12 @@
 #endif
 
 //GATTC CACHE
+#ifdef CONFIG_BT_GATTC_MAX_CACHE_CHAR
+#define UC_BT_GATTC_MAX_CACHE_CHAR      CONFIG_BT_GATTC_MAX_CACHE_CHAR
+#else
+#define UC_BT_GATTC_MAX_CACHE_CHAR      40
+#endif
+
 #ifdef CONFIG_BT_GATTC_CACHE_NVS_FLASH
 #define UC_BT_GATTC_CACHE_NVS_FLASH_ENABLED    CONFIG_BT_GATTC_CACHE_NVS_FLASH
 #else

components/bt/host/bluedroid/common/include/common/bt_target.h

@@ -2247,6 +2247,10 @@ The maximum number of payload octets that the local device can receive in a sing
 #define BTA_DM_AVOID_A2DP_ROLESWITCH_ON_INQUIRY FALSE
 #endif
 
+#ifndef BTA_GATTC_MAX_CACHE_CHAR
+#define BTA_GATTC_MAX_CACHE_CHAR UC_BT_GATTC_MAX_CACHE_CHAR
+#endif
+
 /******************************************************************************
 **
 ** Tracing:  Include trace header file here.