FDS SDK13 : Failure to initialise from time to time

[RichieJH]

So I have been integrating FDS into a project under SDK13. It's based on an example that Hung updated for SDK12.1. So after init of fds the method fds_test_find_and_delete() is called. However I am having trouble with it not initialising from time to time.

When it gets to the garbage collection call in the snippet below I will get back error 0x2 or Failure to Initialize. Now if you skip this and just go to a read or write call, the same error occurs.

static ret_code_t fds_test_find_and_delete (void)
{
    #define FILE_ID     0x1111
    #define REC_KEY     0x2222
    fds_record_desc_t   record_desc;
    fds_find_token_t    ftok;
	
    ftok.page=0;
    ftok.p_addr=NULL;
    // Loop and find records with same ID and rec key and mark them as deleted. 
    while (fds_record_find(FILE_ID, REC_KEY, &record_desc, &ftok) == FDS_SUCCESS)
    {
	fds_record_delete(&record_desc);
	NRF_LOG_INFO("Deleted record ID: %d \r\n",record_desc.record_id);
    }
    // call the garbage collector to empty them, don't need to do this all the time, this is just for demonstration
    ret_code_t ret = fds_gc();
    if (ret != FDS_SUCCESS)
    {
        APP_ERROR_CHECK(ret);
	return ret;
    }
    return NRF_SUCCESS;
}

I have added this to ble_stack_init()

err_code = softdevice_sys_evt_handler_set(sys_evt_dispatch);
APP_ERROR_CHECK(err_code);

And have added this method

static void sys_evt_dispatch(uint32_t sys_evt)
{
    fs_sys_event_handler(sys_evt);
    ble_advertising_on_sys_evt(sys_evt);
}

I have also enabled the module in sdk_config.h. So I think I have pretty much covered the main reasons for a failure to initialise.

And the odd thing was that when I first enabled it as above it did not work, same error. At one point I added fstorage.h even though I wasn't getting any errors and then it started working. Then while I was experimenting with some write record_chunk.p_data structs it suddenly stopped working again.

What am I missing?

[MartinBL]

Hi,

Are you waiting for the FDS_INIT callback after calling fds_init()? It sounds like you are trying to do FDS operations before the module is porperly initiated. Refer to the FDS documentation:

Initialization, like all other operations in FDS that involve writing or erasing flash memory, is an asynchronous operation.

[RichieJH]

Ok I see, perfectly logical. This is quite a key point but doesn't seem to be drawn out very well in the demos nor in the FDS documentation. So what I did was raise the write_flag in the init step, so the next call had to wait until the flag cleared.

static void my_fds_evt_handler(fds_evt_t const * const p_fds_evt)
{
    switch (p_fds_evt->id)
    {
        case FDS_EVT_INIT:
            if (p_fds_evt->result != FDS_SUCCESS)
            {

                APP_ERROR_CHECK(p_fds_evt->result);
                // Initialization failed.
            }
            if (p_fds_evt->result == FDS_SUCCESS)
            {
                write_flag=1;

            }
            break;
	case FDS_EVT_WRITE:
            if (p_fds_evt->result == FDS_SUCCESS)
            {
		write_flag=1;
            }
            break;
        default:
            break;
    }
}

On a quick test this seems to have solved the problem entirely. Surprised it's not suggested as standard practice just like the flag on the other elements of FDS?

[MartinBL]

I suppose the documentation can always be improved.