adding Softdevice BLE (S140) with GPIO attached coprocessor to project without softdevice. hardfault calling existing code after Softdevice active

[rexxdad]

I am extending one of Qorvo's UWB platforms.. adding Softdevice BLE functions..  (which work ok) (this is on sdk 17_1_0)

the coprocessor uses a GPIO connected signaling mechanism,  using interrupts..

calling the existing code after BLE is active causes a hardfault.. 

this is running freetos,  we are in a freetos task. 

I've debugged (using ozone) it to  attempting to setup the interrupt handler for the GPIO pins. 

the existing code calls the nrfx libs 

       return qgpio_pin_irq_configure(&qm33_irq, QGPIO_IRQ_DISABLED);  //according to the doc, a gpio interrupt disable shouldn't impact softdevice.. 

```

enum qerr qgpio_pin_irq_configure(const struct qgpio *qgpio_pin, uint32_t flags)

{

nrfx_err_t r;

enum qerr err;

struct qgpio_cb_data *cb_data;

nrfx_gpiote_in_config_t trigger_config;

uint32_t abs_pin = NRF_GPIO_PIN_MAP(qgpio_pin->port, qgpio_pin->pin_number);  // this sets abs_pin = 25 

/* Init GPIOTE at least once. */

if (!nrfx_gpiote_is_init()) {   // this causes the hardfault.   

   r = nrfx_gpiote_init();

   if (r)

   return QERR_EBUSY;

}

if (flags & QGPIO_IRQ_DISABLED) {

   nrfx_gpiote_in_event_disable(abs_pin);

   nrfx_gpiote_in_uninit(abs_pin);

   return QERR_SUCCESS;

}

```

hardfault window
```
The target stopped in HardFault exception state.

Reason: A fault with configurable priority has been escalated to a HardFault exception at 0x00000000.
```

I don't see any mechanism to cause hardfault on a GPIO pin  with SD active. 
if SD is not active this code works as written 

what am I missing

if I run this code BEFORE setup of softdevice, it works, but softdevice init fails. 

[Hung Bui]

Hi Sam, 
Could you let us know what GPIOTE interrupt level you are using ? 
Some priorities are reserved by the softdevice : https://docs.nordicsemi.com/bundle/sds_s132/page/SDS/s1xx/processor_avail_interrupt_latency/exception_mgmt_sd.html

[rexxdad]

in their build make file they have this , which overrides sdk_config.h
```

target_compile_definitions(

ProjectDefinition PUBLIC GPIOTE_ENABLED=1 NRFX_GPIOTE_ENABLED=0 NRFX_GPIOTE_CONFIG_IRQ_PRIORITY=6

GPIOTE_CONFIG_NUM_OF_LOW_POWER_EVENTS=1

)
```
they do not use either define in their code anywhere. 

[Hung Bui]

It's strange that nrfx_gpiote_is_init() can cause a hardfault, have you stepped inside that function ? 
You may also want to debug the hardfault using a handler: 
An introduction to error handling in nRF5 projects

What do you do in the GPIOTE interrupt ? 

[rexxdad]

I don't know, not my code.. it is the Qorvo UWB handling code which works..
another implementation has BLE Softdevice using S113 sd..   uses a different approach to interrupt setup, but that source is not provided.. 

[Hung Bui]

Hi Sam, th
As showed in the documentation there are some requirement on how interrupt handling should be implemented when using softdevice. You would need to check if there is any other interrupt that may violate the requirement. 

Please try to step the code or use log to see what exactly cause the problem. Have you checked the hardfault handling instruction that I pointed to ? 
I would suggest to get Qorvo support involved as they should have sample that has Softdevice included.