linux-kernel - Re: [PATCH V2 09/11] mtd: nand: read ECC algorithm from the new field

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Date:	Sun, 17 Apr 2016 20:59:38 +0200
From:	Boris Brezillon <boris.brezillon@...e-electrons.com>
To:	Rafał Miłecki <zajec5@...il.com>
Cc:	linux-mtd@...ts.infradead.org, Richard Weinberger <richard@....at>,
	David Woodhouse <dwmw2@...radead.org>,
	Brian Norris <computersforpeace@...il.com>,
	linux-kernel@...r.kernel.org (open list)
Subject: Re: [PATCH V2 09/11] mtd: nand: read ECC algorithm from the new
 field

On Sun, 17 Apr 2016 19:11:42 +0200
Rafał Miłecki <zajec5@...il.com> wrote:

> Now we have all drivers properly setting this new field we can start
> using it. For a very short period of time we should support both values:
> NAND_ECC_SOFT and NAND_ECC_SOFT_BCH treating them the same. It's because
> of_get_nand_ecc_mode may still be setting NAND_ECC_SOFT_BCH.
> 
> Signed-off-by: Rafał Miłecki <zajec5@...il.com>
> ---
> V2: Move SOFT-related code to separated functions
>     Add missing checks for SOFT before checking Hamming vs. BCH
> ---
>  drivers/mtd/nand/nand_base.c | 116 ++++++++++++++++++++++++++-----------------
>  1 file changed, 71 insertions(+), 45 deletions(-)
> 
> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c

[...]

>  
> @@ -4154,7 +4217,9 @@ int nand_scan_tail(struct mtd_info *mtd)
>  	/*
>  	 * If no default placement scheme is given, select an appropriate one.
>  	 */
> -	if (!mtd->ooblayout && (ecc->mode != NAND_ECC_SOFT_BCH)) {
> +	if (!mtd->ooblayout &&
> +	    (ecc->mode == NAND_ECC_SOFT || ecc->mode == NAND_ECC_SOFT_BCH) &&
> +	    ecc->algo != NAND_ECC_BCH) {

Sorry, I got this wrong in my previous review. It should be

	if (!mtd->ooblayout &&
	    ((ecc->mode != NAND_ECC_SOFT &&
	      ecc->mode != NAND_ECC_SOFT_BCH) ||
	     ecc->algo != NAND_ECC_BCH) {

otherwise we're only addressing the software ECC case, and IIRC, some
drivers rely on these default layouts for their HW ECC implementation.

The rest looks good to me.

Thanks,

Boris


-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com