nRF5 SDK 16 BLE startup, failing nrf_atfifo_item_alloc

[Jed Marti]

During BLE startup call to nrf_sdh_enable_request(), nrf_atfifo_item_alloc fails and returns NULL causing a hard fault.

This sounds like an sdk_config.h problem but I don't know where to start looking.

[Vidar Berg]

Hello,

Is the failing call to nrf_atfifo_item_alloc() being made by a SDK module or by your own code? NULL is usually handled by returning NRF_ERROR_NO_MEM back to the app, which should not lead to a fault exception. I would suggest  to first try enabling the HardFault handling library in your project and see if it could help you find out exactly where the fault occurred.

[Jed Marti]

That's how I found out. The top level call is nrf_sdh_enable_request() from the examples which is the first call in ble_stack_init. This call chain hard faulted as a result of NULL being returned by nrf_atfifo_item_alloc. nrf_sdh_enable_request then failed with code 3 which causes the hard stop.

[Jed Marti]

Things behaving differently - I switched to the Linux version (a treat by the way) and followed the request sequence for nrf_sdh_enable_request as follows. The error occurs in a critical region which could be a problem for the debugger but:

nrf_sdh_enable_request
  sdh_request_observer_notify succeeds
  sd_softdevice_enable
     ser_app_hal_hw_init succeeds
     connectivity_reset_low
     nrf_queue_reset
     nrf_queue_reset
     ser_sd_transport_open fails following
       ser_hal_transport_open
        ser_phy_open fails following
         hci_timer_init fails following
           app_timer_create success
             hci_timer_reset fails
                app_timer_stop fails return code 4, switch error code to NRF_ERROR_INTERNAL==3 and return up

Now sounds like something with the timers needed.

Uploading zip problematic for sponsor.

[Jed Marti]

I followed the app_timer_stop a bit farther, it is failing the nrf_atfifo_wspace_req call (which returns NULL). The linker claims I'm only using 25% of RAM so this  must be a memory setup problem. The code in nrf_atfifo_wspace_req is assembly that I'm not competent to interpret.

nrf_sdh_enable_request
sdh_request_observer_notify
sd_softdevice_enable
ser_app_hal_hw_init
connectivity_reset_low
nrf_queue_reset
nrf_queue_reset
ser_sd_transport_open
ser_hal_transport_open
ser_phy_open
hci_timer_init
app_timer_create
hci_timer_reset
app_timer_stop fails return code 4,

further calls by app_timer_stop now...
    timer_req_schedule
      nrf_atfifo_item_alloc returns NULL
        nrf_atfifo_wspace_req --> No calls here, this is what fails.

[Vidar Berg]

I assumed you were working with a standalone application with everything running on the nRF52 device, not a  "serialized setup" with the app code running on a different CPU. Has the application been ported to a different platform (ie not a nordic nRF device)? The atfifo assembly is written for the Cortex m4 architecture.

[Jed Marti]

This is running on an nRF52832 standalone. I'm running the SEGGER IDE (Linux version) JLINK base programmer talking to the board. I don't have a BLE application (phone based) yet, just using nrfconnect but if I can't get bluetooth started, the app is  meaningless. Is the 52832 not an M4 device?

Am I using the wrong bluetooth code? This was setup to use softdevice S112.

[Vidar Berg]

I see. Your project is not set up correctly then. Some of the function calls you listed in your previous response are only used for serialization (ser_app_hal_hw_init, ser_sd_transport_open,..) so that is why I got confused.  I suggest you start with an existing SDK example such as ble_app_blinky and verify that it runs on your board.