[Yaffs] Strange ECC Error

Can somebody please explain the functions below. I am using yaffs/direct,
ECC turned off.

When scanning the emfile during a mount there are ecc errors.

void yaffs_CalcTagsECC(yaffs_Tags *tags)
{
    // Calculate an ecc

    

    unsigned char *b = ((yaffs_TagsUnion *)tags)->asBytes;
    unsigned  i,j;
    unsigned  ecc = 0;
    unsigned bit = 0;
    tags->ecc = 0;                        

    for(i = 0; i < 8; i++)
    {
        for(j = 1; j &0xff; j<<=1)
        {
            bit++;
            if(b[i] & j)
            {
                ecc ^= bit;
            }
        }
    }

    

    tags->ecc = ecc;                    %%%I always
get a high value on ecc approx 64

    
    
}

int  yaffs_CheckECCOnTags(yaffs_Tags *tags)
{
    unsigned ecc = tags->ecc;

    

    yaffs_CalcTagsECC(tags);

    

    ecc ^= tags->ecc;                    %% Now my
ecc increases to approx 4096.

    

    if(ecc && ecc <= 64)
    {
        // TODO: Handle the failure better. Retire?
        unsigned char *b = ((yaffs_TagsUnion *)tags)->asBytes;

        ecc--;

                

        b[ecc / 8] ^= (1 << (ecc & 7));

        

        // Now recvalc the ecc
        yaffs_CalcTagsECC(tags);

        

        return 1; // recovered error
    }
    else if(ecc)
    {
        // Wierd ecc failure value
%%%% I always end up here.
        // TODO Need to do somethiong here
        return -1; //unrecovered error
    }

    

    return 0;
}

//Daniel