From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S932569AbdCVU5j (ORCPT <rfc822;w@1wt.eu>);
        Wed, 22 Mar 2017 16:57:39 -0400
Received: from mail.free-electrons.com ([62.4.15.54]:50198 "EHLO
        mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S932208AbdCVU5c (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Wed, 22 Mar 2017 16:57:32 -0400
Date: Wed, 22 Mar 2017 21:57:28 +0100
From: Boris Brezillon <boris.brezillon@free-electrons.com>
To: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: linux-mtd@lists.infradead.org, laurent.monat@idquantique.com,
        thorsten.christiansson@idquantique.com,
        Enrico Jorns <ejo@pengutronix.de>,
        Jason Roberts <jason.e.roberts@intel.com>,
        Artem Bityutskiy <artem.bityutskiy@linux.intel.com>,
        Dinh Nguyen <dinguyen@kernel.org>, Marek Vasut <marek.vasut@gmail.com>,
        Brian Norris <computersforpeace@gmail.com>,
        Graham Moore <grmoore@opensource.altera.com>,
        David Woodhouse <dwmw2@infradead.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Chuanxiao Dong <chuanxiao.dong@intel.com>,
        Jassi Brar <jaswinder.singh@linaro.org>, linux-kernel@vger.kernel.org,
        Richard Weinberger <richard@nod.at>,
        Cyrille Pitchen <cyrille.pitchen@atmel.com>
Subject: Re: [PATCH v2 11/53] mtd: nand: denali: fix bitflips calculation in
 handle_ecc()
Message-ID: <20170322215728.69e8b566@bbrezillon>
In-Reply-To: <1490191680-14481-12-git-send-email-yamada.masahiro@socionext.com>
References: <1490191680-14481-1-git-send-email-yamada.masahiro@socionext.com>
        <1490191680-14481-12-git-send-email-yamada.masahiro@socionext.com>
X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, 22 Mar 2017 23:07:18 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> +	do {
> +		err_addr = ioread32(denali->flash_reg + ECC_ERROR_ADDRESS);
> +		err_sector = ECC_SECTOR(err_addr);
> +		err_byte = ECC_BYTE(err_addr);
> +
> +		err_cor_info = ioread32(denali->flash_reg + ERR_CORRECTION_INFO);
> +		err_cor_value = ECC_CORRECTION_VALUE(err_cor_info);
> +		err_device = ECC_ERR_DEVICE(err_cor_info);
> +
> +		/* reset the bitflip counter when crossing ECC sector */
> +		if (err_sector != prev_sector)
> +			bitflips = 0;
> +
> +		if (ECC_ERROR_UNCORRECTABLE(err_cor_info)) {
> +			/*
> +			 * if the error is not correctable, need to look at the
> +			 * page to see if it is an erased page. if so, then
> +			 * it's not a real ECC error
> +			 */
> +			ret = -EBADMSG;

You should never return -EBADMSG directly. Just increment
ecc_stats.failed and let the core return -EBADMSG to the upper layer.