On Thu, 3 May 2018 17:50:28 +0530 Abhishek Sahu <absahu@xxxxxxxxxxxxxx> 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@xxxxxxxxxxxxx> > Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx> > --- > * 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()". -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html