Thread (24 messages) 24 messages, 2 authors, 2020-06-05
STALE2227d

[PATCH v10 18/20] mtd: rawnand: Use the ECC framework nand_ecc_is_strong_enough() helper

From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: 2020-06-03 17:58:41
Also in: linux-devicetree
Subsystem: memory technology devices (mtd), nand flash subsystem, the rest · Maintainers: Miquel Raynal, Richard Weinberger, Vignesh Raghavendra, Linus Torvalds

Plus, the new helper has a more "english" name.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/mtd/nand/raw/nand_base.c | 39 +-------------------------------
 1 file changed, 1 insertion(+), 38 deletions(-)
diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index d3e1fc944179..c69d60f791d0 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -5471,43 +5471,6 @@ 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,
@@ -5790,7 +5753,7 @@ 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,
-- 
2.20.1


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