From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.rapiddevelopmentkit.de ([217.6.246.34] helo=root.phytec.de) by casper.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1apXHn-00083q-EV for barebox@lists.infradead.org; Mon, 11 Apr 2016 08:33:32 +0000 Received: from idefix.phytec.de (idefix.phytec.de [172.16.0.10]) by root.phytec.de (Postfix) with ESMTP id 06054A00324 for ; Mon, 11 Apr 2016 10:33:06 +0200 (CEST) From: Teresa Remmet Date: Mon, 11 Apr 2016 10:28:24 +0200 Message-Id: <1460363304-1505-2-git-send-email-t.remmet@phytec.de> In-Reply-To: <1460363304-1505-1-git-send-email-t.remmet@phytec.de> References: <1460363304-1505-1-git-send-email-t.remmet@phytec.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH 2/2] mtd: nand: omap_gpmc: Fix bitflips in empty page To: barebox@lists.infradead.org When using BCH8 decoding, bitflips in an empty page are not checked. This can cause issues if UBI/UBIFS are used. Extend the omap_correct_bch() function to check for them. Code is based on linux mainline mtd/nand/omap2.c driver. Signed-off-by: Teresa Remmet --- drivers/mtd/nand/nand_omap_gpmc.c | 62 ++++++++++++++++++++++++++------------- 1 file changed, 42 insertions(+), 20 deletions(-) diff --git a/drivers/mtd/nand/nand_omap_gpmc.c b/drivers/mtd/nand/nand_omap_gpmc.c index 1d1de5b..a4e6452 100644 --- a/drivers/mtd/nand/nand_omap_gpmc.c +++ b/drivers/mtd/nand/nand_omap_gpmc.c @@ -87,6 +87,9 @@ #define BCH8_MAX_ERROR 8 /* upto 8 bit correctable */ +static const uint8_t bch8_vector[] = {0xf3, 0xdb, 0x14, 0x16, 0x8b, 0xd2, + 0xbe, 0xcc, 0xac, 0x6b, 0xff, 0x99, 0x7b}; + int omap_gpmc_decode_bch(int select_4_8, unsigned char *ecc, unsigned int *err_loc); static const char *ecc_mode_strings[] = { @@ -294,8 +297,11 @@ static int omap_correct_bch(struct mtd_info *mtd, uint8_t *dat, { struct nand_chip *nand = (struct nand_chip *)(mtd->priv); struct gpmc_nand_info *oinfo = (struct gpmc_nand_info *)(nand->priv); - int i, j, eccflag, count, totalcount, actual_eccsize; + int i, j, eccflag, totalcount, actual_eccsize; + const uint8_t *erased_ecc_vec; unsigned int err_loc[8]; + int bitflip_count; + int bch_max_err; int eccsteps = oinfo->nand.ecc.steps; int eccsize = oinfo->nand.ecc.bytes; @@ -304,9 +310,13 @@ static int omap_correct_bch(struct mtd_info *mtd, uint8_t *dat, case OMAP_ECC_BCH8_CODE_HW: eccsize /= eccsteps; actual_eccsize = eccsize; + erased_ecc_vec = bch8_vector; + bch_max_err = BCH8_MAX_ERROR; break; case OMAP_ECC_BCH8_CODE_HW_ROMCODE: actual_eccsize = eccsize - 1; + erased_ecc_vec = bch8_vector; + bch_max_err = BCH8_MAX_ERROR; break; default: dev_err(oinfo->pdev, "invalid driver configuration\n"); @@ -316,37 +326,49 @@ static int omap_correct_bch(struct mtd_info *mtd, uint8_t *dat, totalcount = 0; for (i = 0; i < eccsteps; i++) { - /* check if any ecc error */ + bool is_error_reported = false; + bitflip_count = 0; eccflag = 0; + + /* check for any ecc error */ for (j = 0; (j < actual_eccsize) && (eccflag == 0); j++) { - if (calc_ecc[j] != 0) + if (calc_ecc[j] != 0) { eccflag = 1; + break; + } } if (eccflag == 1) { - eccflag = 0; - for (j = 0; (j < actual_eccsize) && - (eccflag == 0); j++) - if (read_ecc[j] != 0xFF) - eccflag = 1; + if (memcmp(calc_ecc, erased_ecc_vec, actual_eccsize) == 0) { + /* + * calc_ecc[] matches pattern for ECC + * (all 0xff) so this is definitely + * an erased-page + */ + } else { + bitflip_count = nand_check_erased_ecc_chunk( + dat, oinfo->nand.ecc.size, read_ecc, + eccsize, NULL, 0, bch_max_err); + if (bitflip_count < 0) + is_error_reported = true; + } } - count = 0; - if (eccflag == 1) { - count = omap_gpmc_decode_bch(1, calc_ecc, err_loc); - if (count < 0) - return count; - else - totalcount += count; - } + if (is_error_reported) { + bitflip_count = omap_gpmc_decode_bch(1, + calc_ecc, err_loc); + if (bitflip_count < 0) + return bitflip_count; - for (j = 0; j < count; j++) { - if (err_loc[j] < 4096) - dat[err_loc[j] >> 3] ^= + for (j = 0; j < bitflip_count; j++) { + if (err_loc[j] < 4096) + dat[err_loc[j] >> 3] ^= 1 << (err_loc[j] & 7); - /* else, not interested to correct ecc */ + /* else, not interested to correct ecc */ + } } + totalcount += bitflip_count; calc_ecc = calc_ecc + actual_eccsize; read_ecc = read_ecc + eccsize; dat += 512; -- 1.9.1 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox