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mtd: rawnand: Use the ECC framework nand_ecc_is_strong_enough() helper
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Plus, the new helper has a more "english" name.

Signed-off-by: Miquel Raynal <[email protected]>
Link: https://lore.kernel.org/linux-mtd/[email protected]
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miquelraynal committed Sep 30, 2020
1 parent 1e3b37a commit 8c12672
Showing 1 changed file with 1 addition and 38 deletions.
39 changes: 1 addition & 38 deletions drivers/mtd/nand/raw/nand_base.c
Original file line number Diff line number Diff line change
Expand Up @@ -5494,43 +5494,6 @@ int nand_ecc_choose_conf(struct nand_chip *chip,
}
EXPORT_SYMBOL_GPL(nand_ecc_choose_conf);

/*
* Check if the chip configuration meet the datasheet requirements.
* If our configuration corrects A bits per B bytes and the minimum
* required correction level is X bits per Y bytes, then we must ensure
* both of the following are true:
*
* (1) A / B >= X / Y
* (2) A >= X
*
* Requirement (1) ensures we can correct for the required bitflip density.
* Requirement (2) ensures we can correct even when all bitflips are clumped
* in the same sector.
*/
static bool nand_ecc_strength_good(struct nand_chip *chip)
{
struct mtd_info *mtd = nand_to_mtd(chip);
struct nand_ecc_ctrl *ecc = &chip->ecc;
const struct nand_ecc_props *requirements =
nanddev_get_ecc_requirements(&chip->base);
int corr, ds_corr;

if (ecc->size == 0 || requirements->step_size == 0)
/* Not enough information */
return true;

/*
* We get the number of corrected bits per page to compare
* the correction density.
*/
corr = (mtd->writesize * ecc->strength) / ecc->size;
ds_corr = (mtd->writesize * requirements->strength) /
requirements->step_size;

return corr >= ds_corr && ecc->strength >= requirements->strength;
}

static int rawnand_erase(struct nand_device *nand, const struct nand_pos *pos)
{
struct nand_chip *chip = container_of(nand, struct nand_chip,
Expand Down Expand Up @@ -5816,7 +5779,7 @@ static int nand_scan_tail(struct nand_chip *chip)
mtd->oobavail = ret;

/* ECC sanity check: warn if it's too weak */
if (!nand_ecc_strength_good(chip))
if (!nand_ecc_is_strong_enough(&chip->base))
pr_warn("WARNING: %s: the ECC used on your system (%db/%dB) is too weak compared to the one required by the NAND chip (%db/%dB)\n",
mtd->name, chip->ecc.strength, chip->ecc.size,
nanddev_get_ecc_requirements(&chip->base)->strength,
Expand Down

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