Re: [PATCH v2 01/14] mtd: rawnand: helper function for setting up ECC parameters

Boris Brezillon
2018-05-07T08:17:02Z

On Thu, 3 May 2018 17:50:28 +0530
Abhishek Sahu <absahu@codeaurora.org> wrote:

> commit 2c8f8afa7f92 ("mtd: nand: add generic helpers to check,
> match, maximize ECC settings") provides generic helpers which
> drivers can use for setting up ECC parameters.
>
> Since same board can have different ECC strength nand chips so
> following is the logic for setting up ECC strength and ECC step
> size, which can be used by most of the drivers.
>
> 1. If both ECC step size and ECC strength are already set
> (usually by DT) then just check whether this setting
> is supported by NAND controller.
> 2. If NAND_ECC_MAXIMIZE is set, then select maximum ECC strength
> supported by NAND controller.
> 3. Otherwise, try to match the ECC step size and ECC strength closest
> to the chip's requirement. If available OOB size can't fit the chip
> requirement then select maximum ECC strength which can be fit with
> available OOB size with warning.
>
> This patch introduces nand_ecc_param_setup function which calls the
> required helper functions for the above logic. The drivers can use
> this single function instead of calling the 3 helper functions
> individually.
>
> CC: Masahiro Yamada <yamada.masahiro@socionext.com>
> Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
> ---
> * Changes from v1:
>
> NEW PATCH
>
> drivers/mtd/nand/raw/nand_base.c | 42 ++++++++++++++++++++++++++++++++++++++++
> include/linux/mtd/rawnand.h | 3 +++
> 2 files changed, 45 insertions(+)
>
> diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
> index 72f3a89..dd7a984 100644
> --- a/drivers/mtd/nand/raw/nand_base.c
> +++ b/drivers/mtd/nand/raw/nand_base.c
> @@ -6249,6 +6249,48 @@ int nand_maximize_ecc(struct nand_chip *chip,
> }
> EXPORT_SYMBOL_GPL(nand_maximize_ecc);
>
> +/**
> + * nand_ecc_param_setup - Set the ECC strength and ECC step size
> + * @chip: nand chip info structure
> + * @caps: ECC engine caps info structure
> + * @oobavail: OOB size that the ECC engine can use
> + *
> + * Choose the ECC strength according to following logic
> + *
> + * 1. If both ECC step size and ECC strength are already set (usually by DT)
> + * then check if it is supported by this controller.
> + * 2. If NAND_ECC_MAXIMIZE is set, then select maximum ECC strength.
> + * 3. Otherwise, try to match the ECC step size and ECC strength closest
> + * to the chip's requirement. If available OOB size can't fit the chip
> + * requirement then fallback to the maximum ECC step size and ECC strength
> + * and print the warning.
> + *
> + * On success, the chosen ECC settings are set.
> + */
> +int nand_ecc_param_setup(struct nand_chip *chip,
> + const struct nand_ecc_caps *caps, int oobavail)

Can we rename this function "nand_ecc_choose_conf()".