Messages in this thread | | | Date | Tue, 08 May 2018 12:56:13 +0530 | From | Abhishek Sahu <> | Subject | Re: [PATCH v2 04/14] mtd: rawnand: qcom: use the ecc strength from device parameter |
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On 2018-05-07 13:58, Boris Brezillon wrote: > On Thu, 3 May 2018 17:50:31 +0530 > Abhishek Sahu <absahu@codeaurora.org> wrote: > >> Currently the driver uses the ECC strength specified in DT. >> The QPIC/EBI2 NAND supports 4 or 8-bit ECC correction. The same >> kind of board can have different NAND parts so use the ECC >> strength from device parameters if it is not specified in DT. >> >> Signed-off-by: Abhishek Sahu <absahu@codeaurora.org> >> --- >> * Changes from v1: >> >> 1. Removed the custom logic and used the helper fuction. >> >> drivers/mtd/nand/raw/qcom_nandc.c | 31 >> ++++++++++++++++++++++--------- >> 1 file changed, 22 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c >> b/drivers/mtd/nand/raw/qcom_nandc.c >> index b554fb6..a8d71ce 100644 >> --- a/drivers/mtd/nand/raw/qcom_nandc.c >> +++ b/drivers/mtd/nand/raw/qcom_nandc.c >> @@ -2315,13 +2315,21 @@ static int qcom_nand_ooblayout_free(struct >> mtd_info *mtd, int section, >> .free = qcom_nand_ooblayout_free, >> }; >> >> +static int >> +qcom_nandc_calc_ecc_bytes(int step_size, int strength) >> +{ >> + return strength == 4 ? 12 : 16; >> +} >> +NAND_ECC_CAPS_SINGLE(qcom_nandc_ecc_caps, qcom_nandc_calc_ecc_bytes, >> + NANDC_STEP_SIZE, 4, 8); >> + >> static int qcom_nand_host_setup(struct qcom_nand_host *host) >> { >> struct nand_chip *chip = &host->chip; >> struct mtd_info *mtd = nand_to_mtd(chip); >> struct nand_ecc_ctrl *ecc = &chip->ecc; >> struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip); >> - int cwperpage, bad_block_byte; >> + int cwperpage, bad_block_byte, ret; >> bool wide_bus; >> int ecc_mode = 1; >> >> @@ -2334,8 +2342,20 @@ static int qcom_nand_host_setup(struct >> qcom_nand_host *host) >> return -EINVAL; >> } >> >> + cwperpage = mtd->writesize / ecc->size; > > Looks like you're still expecting nand-ecc-step-size to be defined in > the DT, which does not really make sense since you only support one > size: NANDC_STEP_SIZE. > > You should remove the > > if (ecc->size != NANDC_STEP_SIZE) { > dev_err(nandc->dev, "invalid ecc size\n"); > return -EINVAL; > } > > block, then do: > > cwperpage = mtd->writesize / NANDC_STEP_SIZE; > > and finally let the nand_ecc_param_setup() function choose the best > config for you. >
Correct Boris. It only supports one step size so we can remove this DT property. I will make the changes.
>> + >> + /* >> + * Each CW has 4 available OOB bytes which will be protected with >> ECC >> + * so remaining bytes can be used for ECC. >> + */ >> + ret = nand_ecc_param_setup(chip, &qcom_nandc_ecc_caps, >> + mtd->oobsize - (cwperpage << 2)); > > Please stop doing useless optimizations like. That brings nothing and > obfuscates the code a bit more. You say in the comment that each > codeword has 4 protected OOB bytes that can be used by the upper layer, > so just do (cwperpage * 4) and let gcc optimize that for you. >
Sure. I will change it.
Thanks, Abhishek
>> + if (ret) { >> + dev_err(nandc->dev, "No valid ecc settings possible\n"); >> + return ret; >> + } >> + >> wide_bus = chip->options & NAND_BUSWIDTH_16 ? true : false; >> - >> if (ecc->strength >= 8) { >> /* 8 bit ECC defaults to BCH ECC on all platforms */ >> host->bch_enabled = true; >> @@ -2403,7 +2423,6 @@ static int qcom_nand_host_setup(struct >> qcom_nand_host *host) >> >> mtd_set_ooblayout(mtd, &qcom_nand_ooblayout_ops); >> >> - cwperpage = mtd->writesize / ecc->size; >> nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage, >> cwperpage); >> >> @@ -2419,12 +2438,6 @@ static int qcom_nand_host_setup(struct >> qcom_nand_host *host) >> * for 8 bit ECC >> */ >> host->cw_size = host->cw_data + ecc->bytes; >> - >> - if (ecc->bytes * (mtd->writesize / ecc->size) > mtd->oobsize) { >> - dev_err(nandc->dev, "ecc data doesn't fit in OOB area\n"); >> - return -EINVAL; >> - } >> - >> bad_block_byte = mtd->writesize - host->cw_size * (cwperpage - 1) + >> 1; >> >> host->cfg0 = (cwperpage - 1) << CW_PER_PAGE
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