Softdevice disable and enable with freertos issue for radio test

[Vishnu Pradeep]

Hi,

My application is written on top of freertos ble example. I need to integrate radio test example as well for certification. I am running into errors when I try to enable the ble stack after disabling it.

The flow is as follows. 

• Send a command to start radio test.
• disable the softdevice.
• start a timer to enable the softdevice later.
• start the radio test.
• suspend the softdevice task.

When the time elapses

• radio test cancel
• ble init
• resume the softdevice task.

Below is the rough code for the same.

void nrf_sdh_freertos_deinit(void)
{

     // Use the handle to suspend the task.
     if( m_softdevice_task != NULL )
     {
         vTaskSuspend( m_softdevice_task );
     }
}

void nrf_sdh_freertos_reinit(void)
{

     // Use the handle to resume the task.
     if( m_softdevice_task != NULL )
     {
        vTaskResume( m_softdevice_task );
     }


}


void command_handler(){

    if(command_received){
    
            CRITICAL_REGION_ENTER();
            
            ble_conn_params_stop();
            NRF_LOG_INFO("disabling sd %d",nrf_sdh_is_enabled());
            nrf_sdh_disable_request();
            
            start_restart_timer();
            
            memset(&m_test_config, 0, sizeof(m_test_config));
            m_test_config.type              = RX;
            m_test_config.mode              = m_config.mode;
            m_test_config.params.rx.channel = m_config.channel_start;
            m_test_config.params.rx.pattern = m_config.tx_pattern;
            radio_test_start(&m_test_config);
            CRITICAL_REGION_EXIT();
            NRF_LOG_INFO("deiniting the task");
            
            nrf_sdh_freertos_deinit();
    }

}


static void start_restart_timer(void) {
  NRF_LOG_INFO("START TIMER");
   if (pdPASS != xTimerStart(m_restart_timer, OSTIMER_WAIT_FOR_QUEUE))
    {
        APP_ERROR_HANDLER(NRF_ERROR_NO_MEM);
    }

}



static void restart_timeout_handler(TimerHandle_t xTimer)
{ 
UNUSED_PARAMETER(xTimer);
ret_code_t err_code;

  restart_count++;
  NRF_LOG_INFO("resetting count %d",restart_count);
  if(restart_count >= RESTART_TIME_IN_SEC){
    restart_count=0;
    NRF_LOG_INFO("softdevice enabling\r\n");

    radio_test_cancel();

    if(nrf_sdh_is_enabled() == false){
     
      ble_stack_init();
      gap_params_init();
      gatt_init();
      services_init();
      advertising_init();
      conn_params_init();
      peer_manager_init();
      //services_init(); uncommenting this gives NO_MEMORY error
      nrf_sdh_freertos_reinit();
      err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
      APP_ERROR_CHECK(err_code);
    }
    if (pdPASS != xTimerStop(m_restart_timer, OSTIMER_WAIT_FOR_QUEUE))
    {
        APP_ERROR_HANDLER(NRF_ERROR_NO_MEM);
    }


  }
}

But this gave NRF_ERROR_INTERNAL in ble_conn_params_init(). So I added the the check as below inside ble_conn_params_init()

 if(p_instance->timer_id ==NULL)
 {
 p_instance->timer_id = &m_timer_data[i];

        err_code = app_timer_create(&p_instance->timer_id,
                            APP_TIMER_MODE_SINGLE_SHOT,
                            update_timeout_handler);
        if (err_code != NRF_SUCCESS)
        {
            return NRF_ERROR_INTERNAL;
        }
    }

With this I am able to disable the softdevice by sending command and enable again after the timer elapsed. Then able to send command to disable again, but when it tries to enable the softdevice again I am getting the below error.

<error> peer_manager_gcm: Could not acquire conn_state user flags. Increase BLE_CONN_STATE_USER_FLAG_COUNT in the ble_conn_state module.
<error> peer_manager: pm_init failed because gcm_init() returned NRF_ERROR_INTERNAL.
<error> app: ERROR 3 [NRF_ERROR_INTERNAL] at C:\UH\Workspace\nRF_tina\R1_integration\projects\ultrahuman_R1_V0_0_0_17_Master_CD_w\main.c:3736
PC at: 0x000384E1

Is the flow I am doing wrong? How can I disable and enable softdevice for testing the radio ?

Thanks,

Vishnu 

[Susheel Nuguru]

By merely suspending and resuming the softdevice_task you are merely suspending/resuming a task that processes the softdevice events. The BLE stack is still functional(enabled) and if the application is doing anything in the background that generates stack activity, then the softdevice will still generate the events. It is just that your application wont be able to process the events since it disabled not the stack but just the task that processes the events.

The error you are seeing is probably due to overflow of events buffer (just guessing). But it is not the right way to disable/enable softdevice. There has been a lot of other users who have tried this before and there should be a lot of discussions in this forum when you search.

[Vishnu Pradeep]

I am calling nrf_sdh_disable_request(); to disable the softdevice before suspending the softdevice task.

[Susheel Nuguru]

Your problem looks pretty much the same as the one mentioned in this thread. There was a problem in app_timer_delete in app_timer_freertos.c and was fixed in SDKv17. Probably you are using older SDK? If so, please use the patch mentioned in the the thread I linked here to see if it helps your case.

[Vishnu Pradeep]

Thanks for this. Will apply this fix and try. I am using SDK v17 by the way

[Susheel Nuguru]

Great. Hope it is the same issue and the workaround helps.