Re: [PATCH 02/13] mtd: spinand: winbond: Generalize the KV OOB layout

From: Dominique Martinet <dominique.martinet@atmark-techno.com>
To: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Daisuke Mizobuchi <mizo@atmark-techno.com>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	Steam Lin <stlin2@winbond.com>,
	linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 02/13] mtd: spinand: winbond: Generalize the KV OOB layout
Date: Sat, 31 Oct 2026 05:27:33 +0900	[thread overview]
Message-ID: <auT9takcaT1TWj0W@atmark-techno.com> (raw)
In-Reply-To: <20261030-winbond-master-w25nxxlvw-v1-2-91f67407dc8b@bootlin.com>

Miquel Raynal wrote on Fri, Oct 30, 2026 at 06:45:26PM +0100:
> --- a/drivers/mtd/nand/spi/winbond.c
> +++ b/drivers/mtd/nand/spi/winbond.c
> @@ -318,16 +318,11 @@ static int w25n01kv_ooblayout_ecc(struct mtd_info *mtd, int section,
>  	return 0;
>  }
>  
> -static int w25n02kv_ooblayout_ecc(struct mtd_info *mtd, int section,
> -				  struct mtd_oob_region *region)
> +static int w25nxxkv_kw_ooblayout_ecc(struct mtd_info *mtd, int section,
> +				     struct mtd_oob_region *region)
>  {
> -	int num_sections = 4;
> -	int offset = 64;
> -
> -	if (mtd->oobsize == 256) {
> -		num_sections = 8;
> -		offset = 128;
> -	}
> +	unsigned int offset = mtd->oobsize / 2;
> +	unsigned int num_sections = mtd->writesize / 512;

Ah, I couldn't use oobsize for num_sections because of W25N01KV but
using writesize makes sense as well as there's one section per 512 bytes
chunk, and this works for all devices.

Good cleanup!

Reviewed-by: Dominique Martinet <dominique.martinet@atmark-techno.com>

-- 
Dominique

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