[PATCH v3 2/4] mtd: rawnand: gpmi: Add strict ecc strength check

[Han Xu]

Add strict ecc strength check in gpmi_check_ecc() function, which is
same as nand_ecc_is_strong_enough() did. It will check both correct bits
and correct bits per byte to ensure it meets chip required ecc strength.

Signed-off-by: Han Xu <han.xu at nxp.com>

---
Changes since v2:
 - split the ecc check to a single patch
---
---
 drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 24 ++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
index 4144d5937103..9a37f8cc663e 100644
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
@@ -238,9 +238,14 @@ static void gpmi_dump_info(struct gpmi_nand_data *this)
 		geo->block_mark_bit_offset);
 }
 
-static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
+static bool gpmi_check_ecc(struct gpmi_nand_data *this)
 {
+	struct nand_chip *chip = &this->nand;
+	struct mtd_info *mtd = nand_to_mtd(&this->nand);
 	struct bch_geometry *geo = &this->bch_geometry;
+	const struct nand_ecc_props *requirements =
+		nanddev_get_ecc_requirements(&chip->base);
+	int corr, ds_corr;
 
 	/* Do the sanity check. */
 	if (GPMI_IS_MXS(this)) {
@@ -248,7 +253,22 @@ static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
 		if (geo->gf_len == 14)
 			return false;
 	}
-	return geo->ecc_strength <= this->devdata->bch_max_ecc_strength;
+
+	if (geo->ecc_strength > this->devdata->bch_max_ecc_strength)
+		return false;
+
+	/* check ecc strength, same as nand_ecc_is_strong_enough() did */
+	if (requirements->step_size) {
+		corr = mtd->writesize * geo->ecc_strength /
+		       geo->ecc_chunk_size;
+		ds_corr = mtd->writesize * requirements->strength /
+			  requirements->step_size;
+		if (corr < ds_corr ||
+		    geo->ecc_strength < requirements->strength)
+			return false;
+	}
+
+	return true;
 }
 
 /*
-- 
2.17.1