From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mail.free-electrons.com ([62.4.15.54])
 by bombadil.infradead.org with esmtp (Exim 4.89 #1 (Red Hat Linux))
 id 1edktb-00064s-18
 for linux-mtd@lists.infradead.org; Mon, 22 Jan 2018 22:48:56 +0000
Date: Mon, 22 Jan 2018 23:48:42 +0100
From: Boris Brezillon <boris.brezillon@free-electrons.com>
To: Boris Brezillon <boris.brezillon@free-electrons.com>, Richard Weinberger
 <richard@nod.at>, linux-mtd@lists.infradead.org
Cc: David Woodhouse <dwmw2@infradead.org>, Brian Norris
 <computersforpeace@gmail.com>, Marek Vasut <marek.vasut@gmail.com>, Cyrille
 Pitchen <cyrille.pitchen@wedev4u.fr>, Han Xu <han.xu@nxp.com>, Miquel
 Raynal <miquel.raynal@free-electrons.com>
Subject: Re: [PATCH] mtd: nand: gpmi: Add missing nand_read_page_op() in
 gpmi_ecc_read_subpage()
Message-ID: <20180122234842.42949308@bbrezillon>
In-Reply-To: <20180122215148.4502-1-boris.brezillon@free-electrons.com>
References: <20180122215148.4502-1-boris.brezillon@free-electrons.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
List-Id: Linux MTD discussion mailing list <linux-mtd.lists.infradead.org>
List-Unsubscribe: <http://lists.infradead.org/mailman/options/linux-mtd>,
 <mailto:linux-mtd-request@lists.infradead.org?subject=unsubscribe>
List-Archive: <http://lists.infradead.org/pipermail/linux-mtd/>
List-Post: <mailto:linux-mtd@lists.infradead.org>
List-Help: <mailto:linux-mtd-request@lists.infradead.org?subject=help>
List-Subscribe: <http://lists.infradead.org/mailman/listinfo/linux-mtd>,
 <mailto:linux-mtd-request@lists.infradead.org?subject=subscribe>

On Mon, 22 Jan 2018 22:51:48 +0100
Boris Brezillon <boris.brezillon@free-electrons.com> wrote:

> When a subpage read request accesses the ECC block containing the BBM,
> a full page read is required. Commit 25f815f66a14 ("mtd: nand: force
> drivers to explicitly send READ/PROG commands") changed the default
> behavior by forcing drivers to manually issue the READ0 command.
> Unfortunately, the full page read case in gpmi_ecc_read_subpage() has
> been omitted and the nand_read_page_op() call has been moved too far
> in the function leading to a situation where gpmi_ecc_read_page() is
> called without a READ0 command.
> 
> Fix that by adding a call to nand_read_page_op() just before calling
> gpmi_ecc_read_page() in the "access ECC block containing the BBM" case.
> 
> Fixes: 25f815f66a14 ("mtd: nand: force drivers to explicitly send READ/PROG commands")
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> ---
>  drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> index b51db8c85405..3198f5f79a82 100644
> --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> @@ -1215,6 +1215,7 @@ static int gpmi_ecc_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
>  			dev_dbg(this->dev,
>  				"page:%d, first:%d, last:%d, marker at:%d\n",
>  				page, first, last, marker_pos);
> +			nand_read_page_op(chip, page, 0, NULL, 0);
>  			return gpmi_ecc_read_page(mtd, chip, buf, 0, page);

Please ignore this patch: nand_read_page_op() is already called from
gpmi_ecc_read_page().

>  		}
>  	}