MIME-Version: 1.0
In-Reply-To: <20161127163114.24e9b8ad@bbrezillon>
References: <1480183585-592-1-git-send-email-yamada.masahiro@socionext.com>
 <1480183585-592-14-git-send-email-yamada.masahiro@socionext.com> <20161127163114.24e9b8ad@bbrezillon>
From: Masahiro Yamada <yamada.masahiro@socionext.com>
Date: Fri, 2 Dec 2016 13:28:23 +0900
Message-ID: <CAK7LNATt3xDRG94DP5C40PvmaaSdhiQDz1jyHo4mfROV7HaVNA@mail.gmail.com>
Subject: Re: [PATCH 13/39] mtd: nand: denali: increment ecc_stats->corrected
To: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: linux-mtd@lists.infradead.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Marek Vasut <marek.vasut@gmail.com>,
        Brian Norris <computersforpeace@gmail.com>,
        Richard Weinberger <richard@nod.at>,
        David Woodhouse <dwmw2@infradead.org>,
        Cyrille Pitchen <cyrille.pitchen@atmel.com>
Content-Type: text/plain; charset=UTF-8
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1294
Lines: 43

Hi Boris,

2016-11-28 0:31 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> On Sun, 27 Nov 2016 03:05:59 +0900
> Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>
>> Update the number of corrected bit flips when read_page() succeeds.
>>
>> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>> ---
>>
>>  drivers/mtd/nand/denali.c | 3 +++
>>  1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
>> index a6445d9..4cc8945 100644
>> --- a/drivers/mtd/nand/denali.c
>> +++ b/drivers/mtd/nand/denali.c
>> @@ -1162,6 +1162,9 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
>>                       mtd->ecc_stats.failed++;
>>               return 0;
>>       }
>> +
>> +     mtd->ecc_stats.corrected += max_bitflips;
>
> First of all, ecc_stats.corrected should contain the total number of
> bitflips detected on the MTD device, here you're just adding the
> maximum number of bitflips per ECC chunk for the current page, which is
> slightly different.
>
> Then, ecc_stats.corrected seems to be properly updated in handle_ecc()
> [1], so I see no reason to do it here.
>

You are right.

This patch is completely wrong, so I will drop it in v2.


-- 
Best Regards
Masahiro Yamada