LTE: lazy init the task

the LTE task takes about 14K of RAM. With this change the task will only be started when it's needed for the first time. This could be either pycom.lte_modem_en_on_boot(), or lte=LTE() from micropython.

Motivation: pygate+GPY+wifi runs out of memory. With this lazy initialization it works.

Author: peter-pycom

esp32/lte/lteppp.c

@@ -142,25 +142,28 @@ void connect_lte_uart (void) {
 
 
 void lteppp_init(void) {
-    lteppp_lte_state = E_LTE_INIT;
+    if (!xLTETaskHndl)
+    {
+        lteppp_lte_state = E_LTE_INIT;
 
-    xCmdQueue = xQueueCreate(LTE_CMD_QUEUE_SIZE_MAX, sizeof(lte_task_cmd_data_t));
-    xRxQueue = xQueueCreate(LTE_RSP_QUEUE_SIZE_MAX, LTE_AT_RSP_SIZE_MAX + 1);
+        xCmdQueue = xQueueCreate(LTE_CMD_QUEUE_SIZE_MAX, sizeof(lte_task_cmd_data_t));
+        xRxQueue = xQueueCreate(LTE_RSP_QUEUE_SIZE_MAX, LTE_AT_RSP_SIZE_MAX + 1);
 
-    xLTESem = xSemaphoreCreateMutex();
-    xLTE_modem_Conn_Sem = xSemaphoreCreateMutex();
+        xLTESem = xSemaphoreCreateMutex();
+        xLTE_modem_Conn_Sem = xSemaphoreCreateMutex();
 
-    lteppp_pcb = pppapi_pppos_create(&lteppp_netif, lteppp_output_callback, lteppp_status_cb, NULL);
+        lteppp_pcb = pppapi_pppos_create(&lteppp_netif, lteppp_output_callback, lteppp_status_cb, NULL);
 
-    //wait on connecting modem until it is allowed
-    lteppp_modem_conn_state = E_LTE_MODEM_DISCONNECTED;
+        //wait on connecting modem until it is allowed
+        lteppp_modem_conn_state = E_LTE_MODEM_DISCONNECTED;
 
-    xTaskCreatePinnedToCore(TASK_LTE, "LTE", LTE_TASK_STACK_SIZE / sizeof(StackType_t), NULL, LTE_TASK_PRIORITY, &xLTETaskHndl, 1);
+        xTaskCreatePinnedToCore(TASK_LTE, "LTE", LTE_TASK_STACK_SIZE / sizeof(StackType_t), NULL, LTE_TASK_PRIORITY, &xLTETaskHndl, 1);
 
-    lteppp_connstatus = LTE_PPP_IDLE;
+        lteppp_connstatus = LTE_PPP_IDLE;
 #ifdef LTE_DEBUG_BUFF
-    lteppp_log.log = malloc(LTE_LOG_BUFF_SIZE);
+        lteppp_log.log = malloc(LTE_LOG_BUFF_SIZE);
 #endif
+    }
 }
 
 void lteppp_start (void) {

esp32/main.c

@@ -67,7 +67,7 @@ DRAM_ATTR TaskHandle_t xLoRaTimerTaskHndl;
 TaskHandle_t xSigfoxTaskHndl;
 #endif
 #if defined(GPY) || defined (FIPY)
-TaskHandle_t xLTETaskHndl;
+TaskHandle_t xLTETaskHndl = NULL;
 TaskHandle_t xLTEUartEvtTaskHndl;
 TaskHandle_t xLTEUpgradeTaskHndl;
 #endif

esp32/mods/modlte.c

@@ -428,6 +428,7 @@ static void TASK_LTE_UPGRADE(void *pvParameters){
 // Micro Python bindings; LTE class
 
 static mp_obj_t lte_init_helper(lte_obj_t *self, const mp_arg_val_t *args) {
+    lteppp_init();
     const size_t at_cmd_len = LTE_AT_CMD_SIZE_MAX - 4;
     char at_cmd[at_cmd_len];
     lte_modem_conn_state_t modem_state;

esp32/mptask.c

@@ -286,9 +286,9 @@ void TASK_Micropython (void *pvParameters) {
 
     if (!soft_reset) {
     #if defined(GPY) || defined (FIPY)
-        modlte_init0();
         if(config_get_lte_modem_enable_on_boot())
         {
+            modlte_init0();
             // Notify the LTE thread to start
             modlte_start_modem();
         }