[PATCH v2 2/5] mtd: rawnand: sunxi: make the code mode self-explanatory

[Andre Przywara]

Hi,

On 3/27/26 15:05, Richard Genoud wrote:
> In sunxi_nfc_hw_ecc_{read,write}_chunk(), the ECC step was force to 0,
> the reason is not trivial to get when reading the code.
> 
> The explanation is that, from the NAND flash controller perspective, we
> are indeed at step 0 for user data length and ECC errors.
> 
> Just add a const value with an explanation to clarify things.
> 
> Signed-off-by: Richard Genoud <richard.genoud at bootlin.com>

Acked-by: Andre Przywara <andre.przywara at arm.com>

Cheers,
Andre

> ---
>   drivers/mtd/nand/raw/sunxi_nand.c     | 20 ++++++++++++--------
>   drivers/mtd/nand/raw/sunxi_nand_spl.c |  6 ++++--
>   2 files changed, 16 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c
> index 91f7da2c5ce5..9fc9bc5e0198 100644
> --- a/drivers/mtd/nand/raw/sunxi_nand.c
> +++ b/drivers/mtd/nand/raw/sunxi_nand.c
> @@ -758,6 +758,8 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
>   	u32 status;
>   	u32 pattern_found;
>   	int ret;
> +	/* From the controller point of view, we are at step 0 */
> +	const int nfc_step = 0;
>   
>   	if (*cur_off != data_off)
>   		nand->cmdfunc(mtd, NAND_CMD_RNDOUT, data_off, -1);
> @@ -772,7 +774,7 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
>   		return ret;
>   
>   	sunxi_nfc_reset_user_data_len(nfc);
> -	sunxi_nfc_set_user_data_len(nfc, USER_DATA_SZ, 0);
> +	sunxi_nfc_set_user_data_len(nfc, USER_DATA_SZ, nfc_step);
>   
>   	sunxi_nfc_randomizer_enable(mtd);
>   	writel(NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | NFC_ECC_OP,
> @@ -787,7 +789,7 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
>   
>   	pattern_found = readl(nfc->regs + nfc->caps->reg_pat_found);
>   	pattern_found = field_get(NFC_ECC_PAT_FOUND_MSK(nfc), pattern_found);
> -	if (pattern_found & NFC_ECC_PAT_FOUND(0)) {
> +	if (pattern_found & NFC_ECC_PAT_FOUND(nfc_step)) {
>   		u8 pattern = 0xff;
>   
>   		if (unlikely(!(readl(nfc->regs + NFC_REG_PAT_ID(nfc)) & 0x1)))
> @@ -799,7 +801,7 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
>   		return 1;
>   	}
>   
> -	ret = NFC_ECC_ERR_CNT(0, readl(nfc->regs + NFC_REG_ECC_ERR_CNT(nfc, 0)));
> +	ret = NFC_ECC_ERR_CNT(nfc_step, readl(nfc->regs + NFC_REG_ECC_ERR_CNT(nfc, nfc_step)));
>   
>   	memcpy_fromio(data, nfc->regs + NFC_RAM0_BASE, ecc->size);
>   
> @@ -807,7 +809,7 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
>   	sunxi_nfc_randomizer_read_buf(mtd, oob, ecc->bytes + USER_DATA_SZ, true, page);
>   
>   	status = readl(nfc->regs + NFC_REG_ECC_ST);
> -	if (status & NFC_ECC_ERR(0)) {
> +	if (status & NFC_ECC_ERR(nfc_step)) {
>   		/*
>   		 * Re-read the data with the randomizer disabled to identify
>   		 * bitflips in erased pages.
> @@ -830,7 +832,7 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
>   		 * Retrieve the corrected OOB bytes.
>   		 */
>   		sunxi_nfc_user_data_to_buf(readl(nfc->regs +
> -						 NFC_REG_USER_DATA(nfc, 0)),
> +						 NFC_REG_USER_DATA(nfc, nfc_step)),
>   					   oob);
>   
>   		/* De-randomize the Bad Block Marker. */
> @@ -888,6 +890,8 @@ static int sunxi_nfc_hw_ecc_write_chunk(struct mtd_info *mtd,
>   	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
>   	struct nand_ecc_ctrl *ecc = &nand->ecc;
>   	int ret;
> +	/* From the controller point of view, we are at step 0 */
> +	const int nfc_step = 0;
>   
>   	if (data_off != *cur_off)
>   		nand->cmdfunc(mtd, NAND_CMD_RNDIN, data_off, -1);
> @@ -901,10 +905,10 @@ static int sunxi_nfc_hw_ecc_write_chunk(struct mtd_info *mtd,
>   		memcpy(user_data, oob, USER_DATA_SZ);
>   		sunxi_nfc_randomize_bbm(mtd, page, user_data);
>   		writel(sunxi_nfc_buf_to_user_data(user_data),
> -		       nfc->regs + NFC_REG_USER_DATA(nfc, 0));
> +		       nfc->regs + NFC_REG_USER_DATA(nfc, nfc_step));
>   	} else {
>   		writel(sunxi_nfc_buf_to_user_data(oob),
> -		       nfc->regs + NFC_REG_USER_DATA(nfc, 0));
> +		       nfc->regs + NFC_REG_USER_DATA(nfc, nfc_step));
>   	}
>   
>   	if (data_off + ecc->size != oob_off)
> @@ -915,7 +919,7 @@ static int sunxi_nfc_hw_ecc_write_chunk(struct mtd_info *mtd,
>   		return ret;
>   
>   	sunxi_nfc_reset_user_data_len(nfc);
> -	sunxi_nfc_set_user_data_len(nfc, USER_DATA_SZ, 0);
> +	sunxi_nfc_set_user_data_len(nfc, USER_DATA_SZ, nfc_step);
>   
>   	sunxi_nfc_randomizer_enable(mtd);
>   	writel(NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
> diff --git a/drivers/mtd/nand/raw/sunxi_nand_spl.c b/drivers/mtd/nand/raw/sunxi_nand_spl.c
> index 3a5271b49c36..0d1f060cc425 100644
> --- a/drivers/mtd/nand/raw/sunxi_nand_spl.c
> +++ b/drivers/mtd/nand/raw/sunxi_nand_spl.c
> @@ -302,6 +302,8 @@ static int nand_read_page(const struct nfc_config *conf, u32 offs,
>   	int page = offs / conf->page_size;
>   	u32 ecc_st, pattern_found;
>   	int i;
> +	/* From the controller point of view, we are at step 0 */
> +	const int nfc_step = 0;
>   
>   	if (offs % conf->page_size || len % conf->ecc_size ||
>   	    len > conf->page_size || len < 0)
> @@ -343,7 +345,7 @@ static int nand_read_page(const struct nfc_config *conf, u32 offs,
>   		nand_change_column(oob_off);
>   
>   		sunxi_nfc_reset_user_data_len(conf);
> -		sunxi_nfc_set_user_data_len(conf, USER_DATA_SZ, 0);
> +		sunxi_nfc_set_user_data_len(conf, USER_DATA_SZ, nfc_step);
>   
>   		nand_exec_cmd(NFC_DATA_TRANS | NFC_ECC_OP);
>   		/* Get the ECC status */
> @@ -361,7 +363,7 @@ static int nand_read_page(const struct nfc_config *conf, u32 offs,
>   			pattern_found = readl_nfc(conf->caps->reg_pat_found);
>   			pattern_found = field_get(NFC_ECC_PAT_FOUND_MSK(conf),
>   						  pattern_found);
> -			if (pattern_found & NFC_ECC_PAT_FOUND(0))
> +			if (pattern_found & NFC_ECC_PAT_FOUND(nfc_step))
>   				return 1;
>   		}
>