BLE disconnect --> HCI_Reset unexpected behaviour

[Nikolaj_TL]

I am working on a low power mode in a freeRTOS ble application. On a user request the device is to go into low power mode Stop2. 

In order to achieve the lowest power consumption ~2µA (stm32wb55) the ble activity has to be deactivated and the cpu1 & cpu2 has to go into lp-mode. 

In order to deactivate the ble antenna hci_reset is used. The low power mode implemented with hci_reset() works when tested on a Nucleo-STM32wb55 board based on the BLE_HeartRateFreeRTOS example. When I set it up on another project the hci_reset deletes all threads BLE threads (expected), but also deletes the working thread which means it doesn't excecute the the rest of the LP sequence. 

Here is the setup so far:

void LowPowerThread(void *argument)
{  
 
  HAL_EnableDBGStopMode();
  
  for (;;) {
  	
  	osDelay(5000);

  	HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_RESET);  /* Turn off DEBUG LED */
  	hci_reset();	/* resets the Link Layer on an LE Controller (ble_hci_le.h) */
  	LL_C2_PWR_SetPowerMode(LL_PWR_MODE_SHUTDOWN);
  	
  	/* Disable SysTick Interrupt */
  	CLEAR_BIT(SysTick->CTRL, SysTick_CTRL_TICKINT_Msk);
  	HAL_SuspendTick();	/* suspend TIM17 */

  	LL_EXTI_DisableIT_0_31(LL_EXTI_LINE_ALL_0_31 & ~(LL_EXTI_LINE_6)); /* Disable all interrupts except from WakeUp Pin*/
  	LL_EXTI_DisableIT_32_63(LL_EXTI_LINE_ALL_32_63);
  	HAL_PWREx_EnterSTOP2Mode(PWR_STOPENTRY_WFI);  
  	
  	/* ... STOP Mode ... */
  	
  	HAL_ResumeTick();
  	SYSCLKConfig_FromSTOP();
  	HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_SET);  /* Turn on DEBUG LED */
  }
}

 
Here is a screenshot before the hci_reset command is called and after.
Before:

OBS: here the LowPowerThread is called RelibableJourney
After:

Any guidance in understanding how the hci_reset() can delete threads and thereby omit the excecution of code in a thread is greatly appreciated 

[Nikolaj_TL · Accepted solution]

FreeRTOS Thread stack overflow caused the inconsistent behaviour. Resolved an hci_reset works as expected