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From:   Naga Sureshkumar Relli <nagasure@xilinx.com>
To:     Boris Brezillon <boris.brezillon@collabora.com>
CC:     "miquel.raynal@bootlin.com" <miquel.raynal@bootlin.com>,
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Subject: RE: [LINUX PATCH v17 1/2] mtd: rawnand: nand_micron: Do not over
 write driver's read_page()/write_page()
Thread-Topic: [LINUX PATCH v17 1/2] mtd: rawnand: nand_micron: Do not over
 write driver's read_page()/write_page()
Thread-Index: AQHVKxEOKM99KajnN0G2IiFegkrxG6atgBaAgABKdoA=
Date:   Wed, 26 Jun 2019 11:22:33 +0000
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 <20190626084807.3f06e718@collabora.com>
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Hi Boris,

> -----Original Message-----
> From: Boris Brezillon <boris.brezillon@collabora.com>
> Sent: Wednesday, June 26, 2019 12:18 PM
> To: Naga Sureshkumar Relli <nagasure@xilinx.com>
> Cc: miquel.raynal@bootlin.com; helmut.grohne@intenta.de; richard@nod.at;
> dwmw2@infradead.org; computersforpeace@gmail.com; marek.vasut@gmail.com;
> vigneshr@ti.com; bbrezillon@kernel.org; yamada.masahiro@socionext.com; li=
nux-
> mtd@lists.infradead.org; linux-kernel@vger.kernel.org
> Subject: Re: [LINUX PATCH v17 1/2] mtd: rawnand: nand_micron: Do not over=
 write
> driver's read_page()/write_page()
>=20
> On Mon, 24 Jun 2019 22:46:29 -0600
> Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com> wrote:
>=20
> > Add check before assigning chip->ecc.read_page() and
> > chip->ecc.write_page()
> >
> > Signed-off-by: Naga Sureshkumar Relli
> > <naga.sureshkumar.relli@xilinx.com>
> > ---
> >  drivers/mtd/nand/raw/nand_micron.c | 7 +++++--
> >  1 file changed, 5 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/mtd/nand/raw/nand_micron.c
> > b/drivers/mtd/nand/raw/nand_micron.c
> > index cbd4f09ac178..565f2696c747 100644
> > --- a/drivers/mtd/nand/raw/nand_micron.c
> > +++ b/drivers/mtd/nand/raw/nand_micron.c
> > @@ -500,8 +500,11 @@ static int micron_nand_init(struct nand_chip *chip=
)
> >  		chip->ecc.size =3D 512;
> >  		chip->ecc.strength =3D chip->base.eccreq.strength;
> >  		chip->ecc.algo =3D NAND_ECC_BCH;
> > -		chip->ecc.read_page =3D micron_nand_read_page_on_die_ecc;
> > -		chip->ecc.write_page =3D micron_nand_write_page_on_die_ecc;
> > +		if (!chip->ecc.read_page)
> > +			chip->ecc.read_page =3D micron_nand_read_page_on_die_ecc;
> > +
> > +		if (!chip->ecc.write_page)
> > +			chip->ecc.write_page =3D micron_nand_write_page_on_die_ecc;
>=20
> That's wrong, if you don't want on-die ECC to be used, simply don't set n=
and-ecc-mode to "on-
> die".
Ok. But if we want to use on-die ECC then you mean to say it is mandatory t=
o use micron_nand_read/write_page_on_die_ecc()?

Regards,
Naga Sureshkumar Relli
>=20
> >
> >  		if (ondie =3D=3D MICRON_ON_DIE_MANDATORY) {
> >  			chip->ecc.read_page_raw =3D nand_read_page_raw_notsupp;