[PATCH 5.4 135/215] mtd: rawnand: brcmnand: correctly verify erased pages

[Greg Kroah-Hartman]

From: Ãlvaro FernÃndez Rojas <noltari@xxxxxxxxx>

commit dcb351c03f2fa6a599de1061b174167e03ee312b upstream.

The current code checks that the whole OOB area is erased.
This is a problem when JFFS2 cleanmarkers are added to the OOB, since it will
fail due to the usable OOB bytes not being 0xff.
Correct this by only checking that data and ECC bytes aren't 0xff.

Fixes: 02b88eea9f9c ("mtd: brcmnand: Add check for erased page bitflips")
Signed-off-by: Ãlvaro FernÃndez Rojas <noltari@xxxxxxxxx>
Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Link: https://lore.kernel.org/linux-mtd/20200512082451.771212-1-noltari@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/mtd/nand/raw/brcmnand/brcmnand.c |   19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
@@ -1790,28 +1790,31 @@ static int brcmnand_read_by_pio(struct m
 static int brcmstb_nand_verify_erased_page(struct mtd_info *mtd,
 		  struct nand_chip *chip, void *buf, u64 addr)
 {
-	int i, sas;
-	void *oob = chip->oob_poi;
+	struct mtd_oob_region ecc;
+	int i;
 	int bitflips = 0;
 	int page = addr >> chip->page_shift;
 	int ret;
+	void *ecc_bytes;
 	void *ecc_chunk;
 
 	if (!buf)
 		buf = nand_get_data_buf(chip);
 
-	sas = mtd->oobsize / chip->ecc.steps;
-
 	/* read without ecc for verification */
 	ret = chip->ecc.read_page_raw(chip, buf, true, page);
 	if (ret)
 		return ret;
 
-	for (i = 0; i < chip->ecc.steps; i++, oob += sas) {
+	for (i = 0; i < chip->ecc.steps; i++) {
 		ecc_chunk = buf + chip->ecc.size * i;
-		ret = nand_check_erased_ecc_chunk(ecc_chunk,
-						  chip->ecc.size,
-						  oob, sas, NULL, 0,
+
+		mtd_ooblayout_ecc(mtd, i, &ecc);
+		ecc_bytes = chip->oob_poi + ecc.offset;
+
+		ret = nand_check_erased_ecc_chunk(ecc_chunk, chip->ecc.size,
+						  ecc_bytes, ecc.length,
+						  NULL, 0,
 						  chip->ecc.strength);
 		if (ret < 0)
 			return ret;