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Date: Fri, 24 Jul 2009 21:24:01 +0400
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Subject: Re: abuse of nand_correct_data in tmio_nand driver
From: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
To: Atsushi Nemoto <anemo@mba.ocn.ne.jp>, Ian Molton <spyro@f2s.com>
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2009/7/23 Atsushi Nemoto <anemo@mba.ocn.ne.jp>:
> On Thu, 23 Jul 2009 12:34:43 +0530, vimal singh <vimal.newwork@gmail.com>=
 wrote:
>> > OK, but I still feel duplicating nand_ecc code is not so good. =A0How
>> > about splitting nand_correct_data into two parts? =A0A pure calculatio=
n
>> > function and a wrapper for mtd interface. =A0Like this:
>>
>> But I do not see any thing extra, which you achieve from this
>> wrapper... =A0Is this a prototype, and you want to handle above scenario
>> in this wrapper (calling 'nand_correct_data' multiple times based on
>> something, probably 'ecc.bytes')?
>
> Yes, if we have __nand_correct_data(buf, read_ecc, calc_ecc, eccsize)
> which do job based on its eccsize argument, the ecc.correct function
> of the tmio_nand driver can be implemented like this:
>
> int tmio_nand_correct_data(struct mtd_info *mtd, unsigned char *buf,
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0unsigned char *read_ecc, unsigned char *ca=
lc_ecc)
> {
> =A0 =A0 =A0 =A0int r0, r1;
>
> =A0 =A0 =A0 =A0/* assume ecc.size =3D 512 and ecc.bytes =3D 6 */
> =A0 =A0 =A0 =A0r0 =3D __nand_correct_data(buf, read_ecc, calc_ecc, 256);
> =A0 =A0 =A0 =A0if (r0 < 0)
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0return r0;
> =A0 =A0 =A0 =A0r1 =3D __nand_correct_data(buf + 256, read_ecc + 3, calc_e=
cc + 3, 256);
> =A0 =A0 =A0 =A0if (r1 < 0)
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0return r1;
> =A0 =A0 =A0 =A0return r0 | r1;
> }
>
> Note that this is not tested at all since I do not have tmio device.

This seems to be the thing that was initially ment by Zaurus kernels, so
this if Ian doesn't object,

Acked-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>

--=20
With best wishes
Dmitry