Handling Fds_write event before reading from flash.

[saiteja]

Hi,

I am having a 324 byte,a 420 bytes of array stored in flash,now i am updating these array with 360 bytes. in fds_event_handler in the case FDS_EVT_WRITE i am reading flash again

static void fds_event_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) 		
            {
            // Initialization failed.
            } 		
            break; 	

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

Ques: while reading i am getting last four or five rows values as zeros.

Suggestion: I am thinking that write event is not properly handled, means writing is not done properly.

Code for fds_read :

static ret_code_t fds_read(uint16_t record_read)
{
    fds_flash_record_t  flash_record;
    fds_record_desc_t   record_desc;
    fds_find_token_t    ftok ={0};//Important, make sure you zero init the ftok token

    float *data;

    uint32_t err_code;

    if(PRINT_DEBUG)
    {
         NRF_LOG_PRINTF("Start searching... \r\n");
    }

    // Loop until all records with the given key and file ID have been found.

    while (fds_record_find(FILE_ID, REC_KEY+record_read, &record_desc, &ftok) == FDS_SUCCESS)
    {
         printf("in read:\n");

         err_code = fds_record_open(&record_desc, &flash_record);

         if ( err_code != FDS_SUCCESS)
         {
             return err_code;
         }
         if(PRINT_DEBUG)
         {
         NRF_LOG_PRINTF("Found Record ID = %d reading record: %x,%d\r\n",record_desc.record_id,REC_KEY+record_read,record_read);

         NRF_LOG_PRINTF("Data = ");
     }

     // Access the record through the flash_record structure.

     data = (float *) flash_record.p_data;

     int i=0;

     for(int j=0; j<(flash_record.p_header->tl.length_words)/COLUMNS_FOR_MODEL;j++)
     {
         for(int k=0; k<COLUMNS_FOR_MODEL;k++,i++)
         {
             model[j][k] = data[i];
                 
             if(PRINT_DEBUG)
             {
                 NRF_LOG_PRINTF("%f\t",model[j][k]);
             }
         }
     }

     update_model(model,record_read);

     if(PRINT_DEBUG)
     {
         NRF_LOG_PRINTF("\r\n");
     }

     // Close the record when done.

     err_code = fds_record_close(&record_desc);

     if (err_code != FDS_SUCCESS)
     {
         return err_code;
     }        
    
    return NRF_SUCCESS;
}

Code for fds_write:

static ret_code_t fds_write(float  model_array[][3],uint16_t record_write,uint16_t size_of_model)
{
    fds_find_token_t    ftok
    ftok.page=0;
    ftok.p_addr=NULL;
    fds_record_t        record;
    fds_record_desc_t   record_desc;
    fds_record_chunk_t  record_chunk;
    record_chunk.p_data         = model_array;
    record_chunk.length_words   = size_of_model*3;

    // Set up record.

    record.file_id              =  FILE_ID;
    record.key                  =  REC_KEY+record_write;
    record.data.p_chunks        =  &record_chunk;
    record.data.num_chunks      =  1;

    if(fds_record_find(FILE_ID, REC_KEY+record_write, &record_desc, &ftok) == FDS_SUCCESS)
    {
         fds_record_delete(&record_desc);
         
         ret = fds_gc();

         fds_record_update(&record_desc,&record);

    }

    NRF_LOG_PRINTF("%d\n",record_write);

    return NRF_SUCCESS;
}

Using the same write code i am able to write into flash if i clear the flash first.and able to read also.

I just need that at run time Fds_write should update flash and fds_read able to read from flash properly after write and then other function should work.

Any help would be appreciated.

[saiteja]

Thanks Petter for clearing things.