[Yaffs] Can't enable ecc check for yaffs

Hi, sir
I cannot enable ecc check in mtd, the message in nand.c, func int
nand_write_page (),
printk (KERN_WARNING "Writing data without ECC to NAND-FLASH is not
recommended\n");

In mtd/nand.c,
static int nand_write_page (struct mtd_info *mtd, struct nand_chip
*this, int page, u_char *oob_buf,  struct nand_oobinfo *oobsel)
{
    int     i, status;
    u_char    ecc_code[6], *oob_data;
    int    eccmode = oobsel->useecc ? this->eccmode : NAND_ECC_NONE;
//??????? I have initialize the eccmode to NAND_ECC_HW3_512,
...
}

I have enable the ecc check in mizi linux 2.4.18 for ARM2410.

Thank you