From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 93714C5CFFE for ; Mon, 10 Dec 2018 14:51:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 66E1F20851 for ; Mon, 10 Dec 2018 14:51:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 66E1F20851 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728097AbeLJOvB convert rfc822-to-8bit (ORCPT ); Mon, 10 Dec 2018 09:51:01 -0500 Received: from mail.bootlin.com ([62.4.15.54]:37630 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727062AbeLJOvA (ORCPT ); Mon, 10 Dec 2018 09:51:00 -0500 Received: by mail.bootlin.com (Postfix, from userid 110) id 5EF5820CEB; Mon, 10 Dec 2018 15:50:58 +0100 (CET) Received: from xps13 (aaubervilliers-681-1-79-44.w90-88.abo.wanadoo.fr [90.88.21.44]) by mail.bootlin.com (Postfix) with ESMTPSA id E516320CE8; Mon, 10 Dec 2018 15:50:57 +0100 (CET) Date: Mon, 10 Dec 2018 15:50:57 +0100 From: Miquel Raynal To: Liang Yang Cc: Boris Brezillon , Jianxin Pan , , Yixun Lan , David Woodhouse , Brian Norris , Marek Vasut , Richard Weinberger , Jerome Brunet , Neil Armstrong , Martin Blumenstingl , Carlo Caione , Kevin Hilman , Rob Herring , Jian Hu , Hanjie Lin , Victor Wan , , , Subject: Re: [PATCH v7 2/2] mtd: rawnand: meson: add support for Amlogic NAND flash controller Message-ID: <20181210155057.38788656@xps13> In-Reply-To: <79a797c2-f37f-7f7c-e907-2d3c2283ec2d@amlogic.com> References: <1542386439-30166-1-git-send-email-jianxin.pan@amlogic.com> <1542386439-30166-3-git-send-email-jianxin.pan@amlogic.com> <20181207102456.1dc67e07@xps13> <823825a3-86fb-9a20-ae29-85cc52d44093@amlogic.com> <20181210123809.5ade45c4@bbrezillon> <79a797c2-f37f-7f7c-e907-2d3c2283ec2d@amlogic.com> Organization: Bootlin X-Mailer: Claws Mail 3.17.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Liang, Liang Yang wrote on Mon, 10 Dec 2018 20:12:39 +0800: > On 2018/12/10 19:38, Boris Brezillon wrote: > > On Mon, 10 Dec 2018 19:23:46 +0800 > > Liang Yang wrote: > > > >>>> + mtd->ecc_stats.failed++; > >>>> + continue; > >>>> + } > >>>> + mtd->ecc_stats.corrected += ECC_ERR_CNT(*info); > >>>> + bitflips = max_t(u32, bitflips, ECC_ERR_CNT(*info)); > >>>> + } > >>> > >>> Are you sure you handle correctly empty pages with bf? > >>> >> if scramble is enable, i would say yes here. > >> when scramble is disabled, i am considering how to use the helper > >> nand_check_erased_ecc_chunk, but it seems that i can't get the ecc > >> bytes which is caculated by ecc engine.by the way, nfc dma doesn't send > >> out the ecc parity bytes. > > > > Even if the ECC engine is disabled? > > > No. > When ECC engine is disabled, it can read the ecc parity bytes ; but there is another problem that i need to consider how code struct looks better when reading error with ecc opened and then try to raw read. > Is there a good idea? When reading with ECC enabled, in case of uncorrectable error you must re-read without ECC, then check if the page is empty or not with the core helpers (nand_check_erased_*()). Is this what you meant? Thanks, Miquèl