From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bxU62-00040b-2J for barebox@lists.infradead.org; Fri, 21 Oct 2016 07:18:31 +0000 Date: Fri, 21 Oct 2016 09:18:08 +0200 From: Sascha Hauer Message-ID: <20161021071808.ygaw53zjn3x5ns6f@pengutronix.de> References: <1476970807-43811-1-git-send-email-c.hemp@phytec.de> <1476970807-43811-2-git-send-email-c.hemp@phytec.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1476970807-43811-2-git-send-email-c.hemp@phytec.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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: Re: [PATCH 2/2] mtd: nand: nand_mxs: Fix readtotal calculation To: Christian Hemp Cc: barebox@lists.infradead.org, Stefan Lengfeld On Thu, Oct 20, 2016 at 03:40:07PM +0200, Christian Hemp wrote: > The calculation of readtotal must be bit alligend. If not the bch core > finds bit flips in every page, because readtotal is too small. > This bug was mostly introduced since commit "51061a9 mtd: nand: nand_mxs: > Add subpage read support". Is this somehow related to: http://lists.infradead.org/pipermail/linux-mtd/2016-June/068243.html Or is this another topic? Sascha > > Tested with: > nand: NAND device: Manufacturer ID: 0x01, Chip ID: 0xd3 (AMD/Spansion > S34ML08G2), 1024MiB, page size: 2048, OOB size: 128 > > nand: NAND device: Manufacturer ID: 0x2c, Chip ID: 0xdc (Micron > MT29F4G08ABADAWP), 512MiB, page size: 2048, OOB size: 64 > > nand: NAND device: Manufacturer ID: 0xec, Chip ID: 0xd3 (Samsung NAND > 1GiB 3,3V 8-bit), 1024MiB, page size: 2048, OOB size: 64 > > Signed-off-by: Christian Hemp > Signed-off-by: Stefan Lengfeld > --- > drivers/mtd/nand/nand_mxs.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/mtd/nand/nand_mxs.c b/drivers/mtd/nand/nand_mxs.c > index fe955e8..cba0bee 100644 > --- a/drivers/mtd/nand/nand_mxs.c > +++ b/drivers/mtd/nand/nand_mxs.c > @@ -728,15 +728,15 @@ static int __mxs_nand_ecc_read_page(struct mtd_info *mtd, struct nand_chip *nand > uint32_t corrected = 0, failed = 0; > uint8_t *status; > unsigned int max_bitflips = 0; > - int i, ret, readtotal, nchunks, eccstrength, ecc_parity_size; > + int i, ret, readtotal, nchunks, eccstrength; > > eccstrength = mxs_nand_get_ecc_strength(mtd->writesize, mtd->oobsize); > > readlen = roundup(readlen, MXS_NAND_CHUNK_DATA_CHUNK_SIZE); > nchunks = mxs_nand_ecc_chunk_cnt(readlen); > - ecc_parity_size = 13 * eccstrength / 8; > - readtotal = MXS_NAND_METADATA_SIZE + > - (MXS_NAND_CHUNK_DATA_CHUNK_SIZE + ecc_parity_size) * nchunks; > + readtotal = MXS_NAND_METADATA_SIZE; > + readtotal += MXS_NAND_CHUNK_DATA_CHUNK_SIZE * nchunks; > + readtotal += DIV_ROUND_UP(13 * eccstrength * nchunks, 8); > > mxs_nand_config_bch(mtd, readtotal); > > -- > 1.9.1 > > > _______________________________________________ > barebox mailing list > barebox@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/barebox > -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox