linux-kernel - Re: [PATCH] mtd: nand: gpmi: add proper raw access support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20140911164536.796f1012@bbrezillon>
Date:	Thu, 11 Sep 2014 16:45:36 +0200
From:	Boris BREZILLON <boris.brezillon@...e-electrons.com>
To:	Huang Shijie <shijie8@...il.com>
Cc:	David Woodhouse <dwmw2@...radead.org>,
	Brian Norris <computersforpeace@...il.com>,
	linux-mtd@...ts.infradead.org, Huang Shijie <b32955@...escale.com>,
	Mike Voytovich <mvoytovich@...pal.com>,
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	Roy Lee <roylee@...pal.com>
Subject: Re: [PATCH] mtd: nand: gpmi: add proper raw access support

On Thu, 11 Sep 2014 22:29:32 +0800
Huang Shijie <shijie8@...il.com> wrote:

> On Wed, Sep 10, 2014 at 10:55:39AM +0200, Boris BREZILLON wrote:
>  +static int gpmi_ecc_read_page_raw(struct mtd_info *mtd,
> > +				  struct nand_chip *chip, uint8_t *buf,
> > +				  int oob_required, int page)
> > +{
> > +	struct gpmi_nand_data *this = chip->priv;
> > +	struct bch_geometry *nfc_geo = &this->bch_geometry;
> > +	int eccsize = nfc_geo->ecc_chunk_size;
> > +	int eccbytes = DIV_ROUND_UP(nfc_geo->ecc_strength * nfc_geo->gf_len,
> > +				    8);
> 
> In actually, the ECC can be _NOT_ bytes aligned.
> you should not round up to byte.

You mean, on the NAND storage ? That would be weird, but I'll check.

When accessing in raw mode I'm not using the ECC engine (or at least
that's what I'm trying to achieve when using read_buf and not
gpmi_ecc_read_page).



-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/