[PATCH v7 2/2] mtd: rawnand: nuvoton: add new driver for the Nuvoton MA35 SoC

[Hui-Ping Chen]

Dear Sascha,


Thank you for your reply.


On 2024/10/18 下午 05:40, Sascha Hauer wrote:
> On Fri, Oct 18, 2024 at 02:25:19AM +0000, Hui-Ping Chen wrote:
>> +static int ma35_nfi_ecc_check(struct nand_chip *chip, u8 *addr)
>> +{
>> +	struct ma35_nand_info *nand = nand_get_controller_data(chip);
>> +	struct mtd_info *mtd = nand_to_mtd(chip);
>> +	int i, j, nchunks = 0;
>> +	int report_err = 0;
>> +	int err_cnt = 0;
>> +	u32 status;
>> +
>> +	nchunks = mtd->writesize / chip->ecc.steps;
>> +	if (nchunks < 4)
>> +		nchunks = 1;
>> +	else
>> +		nchunks /= 4;
>> +
>> +	for (j = 0; j < nchunks; j++) {
>> +		status = readl(nand->regs + MA35_NFI_REG_NANDECCES0 + j * 4);
>> +		if (!status)
>> +			continue;
>> +
>> +		for (i = 0; i < 4; i++) {
>> +			if ((status & ECC_STATUS_MASK) == 0x01) {
>> +				/* Correctable error */
>> +				err_cnt = (status >> 2) & ECC_ERR_CNT_MASK;
>> +				ma35_nfi_correct(chip, j * 4 + i, err_cnt, addr);
>> +				report_err += err_cnt;
> This is still wrong. This should be
>
> 				report_err = max(report_err, err_cnt);
>
> You have to search for the subpage that has the most bitflips and return
> the number of bitflips on that subpage, *not* the total amount of errors
> on the whole page.
>
> That said, the statistic counter should still count the total number of
> bitflips occurred.

I re-examined the return value of read_page, and it indeed needs to 
return the

maximum bitflips for the subpage. I will correct this return value.

Thank you.


> Sascha
>
>> +			} else {
>> +				/* Uncorrectable error */
>> +				dev_warn(nand->dev, "uncorrectable error! 0x%4x\n", status);
>> +				return -EBADMSG;
>> +			}
>> +			status >>= 8;
>> +		}
>> +	}
>> +	return report_err;
>> +}
>> +

Best regards,

Hui-Ping Chen