Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <1558117914-35807-1-git-send-email-kdasu.kdev@gmail.com>
 <1558117914-35807-2-git-send-email-kdasu.kdev@gmail.com> <20190520144436.67e42f00@xps13>
In-Reply-To: <20190520144436.67e42f00@xps13>
From:   Kamal Dasu <kdasu.kdev@gmail.com>
Date:   Mon, 20 May 2019 13:31:52 -0400
Message-ID: <CAC=U0a0bZHgM2yQzz5SupRNWcBg7rpqpGh_o9cvSQNNKsSp9Cg@mail.gmail.com>
Subject: Re: [PATCH 2/2] mtd: nand: raw: brcmnand: fallback to detected
 ecc-strength, ecc-step-size
To:     Miquel Raynal <miquel.raynal@bootlin.com>
Cc:     MTD Maling List <linux-mtd@lists.infradead.org>,
        bcm-kernel-feedback-list@broadcom.com,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Brian Norris <computersforpeace@gmail.com>,
        Richard Weinberger <richard@nod.at>,
        David Woodhouse <dwmw2@infradead.org>,
        Marek Vasut <marek.vasut@gmail.com>,
        Vignesh Raghavendra <vigneshr@ti.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Will make the changes and send a V2 patch.

On Mon, May 20, 2019 at 8:44 AM Miquel Raynal <miquel.raynal@bootlin.com> w=
rote:
>
> Hi Kamal,
>
> Kamal Dasu <kdasu.kdev@gmail.com> wrote on Fri, 17 May 2019 14:29:55
> -0400:
>
> > This change supports nand-ecc-step-size and nand-ecc-strenght fields in
>
>                                                        strength
>
> > brcmnand dt node to be  optional.
>
>            DT            ^ extra space
>
> > see: Documentation/devicetree/bindings/mtd/brcm,brcmnand.txt
> >
> > If both nand-ecc-strength and nand-ecc-step-size are not specified in
> > device tree node for NAND, nand_base driver does detect onfi ext ecc
>
> s/nand_base driver/the raw NAND layer/
> s/onfi/ONFI/
> s/ecc/ECC/
>
> What is "ext"? Please use plain English here.
>
> > info from ONFI extended parameter page for parts using ONFI >=3D 2.1. I=
n
>
> s/info/information/
>
> > case of non-onfi NAND there could be a nand_id table entry with the ecc
>
> s/ecc/ECC/
>
> > info. If there is a valid  device tree entry for nand-ecc-strength and
> > nand-ecc-step-size fields it still shall override the detected values.
> >
> > Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
> > ---
> >  drivers/mtd/nand/raw/brcmnand/brcmnand.c | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> >
> > diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nan=
d/raw/brcmnand/brcmnand.c
> > index ce0b8ff..e967b30 100644
> > --- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> > +++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> > @@ -2144,6 +2144,16 @@ static int brcmnand_setup_dev(struct brcmnand_ho=
st *host)
> >               return -EINVAL;
> >       }
> >
> > +     if (!(chip->ecc.size > 0 && chip->ecc.strength > 0) &&
>
> Is the case where only size OR strength is valid handled?

Both strength and need to be valid, else the driver will behave like
before and will fail the probe.

>
> > +         (chip->base.eccreq.strength > 0 &&
> > +          chip->base.eccreq.step_size > 0)) {
> > +             /* use detected ecc parameters */
>
>                    Use          ECC
>
> > +             chip->ecc.size =3D chip->base.eccreq.step_size;
> > +             chip->ecc.strength =3D chip->base.eccreq.strength;
> > +             pr_info("Using detected nand-ecc-step-size %d, nand-ecc-s=
trength %d\n",
> > +                     chip->ecc.size, chip->ecc.strength);
> > +     }
> > +
> >       switch (chip->ecc.size) {
> >       case 512:
> >               if (chip->ecc.algo =3D=3D NAND_ECC_HAMMING)
>
>
> Thanks,
> Miqu=C3=A8l

Kamal