[PATCH v2 2/5] mtd: rawnand: sunxi: make the code mode self-explanatory
Michael Nazzareno Trimarchi
michael at amarulasolutions.com
Fri Mar 27 15:40:45 CET 2026
Hi
On Fri, Mar 27, 2026 at 3:05 PM Richard Genoud
<richard.genoud at bootlin.com> 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>
> ---
> 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;
> }
>
Reviewed-By: Michael Trimarchi <michael at amarulasolutions.com>
--
Michael Nazzareno Trimarchi
Co-Founder & Chief Executive Officer
M. +39 347 913 2170
michael at amarulasolutions.com
__________________________________
Amarula Solutions BV
Joop Geesinkweg 125, 1114 AB, Amsterdam, NL
T. +31 (0)85 111 9172
info at amarulasolutions.com
www.amarulasolutions.com
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