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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 01C1EC4338F for ; Mon, 23 Aug 2021 14:16:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D8020613AD for ; Mon, 23 Aug 2021 14:16:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230036AbhHWORP (ORCPT ); Mon, 23 Aug 2021 10:17:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55582 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229909AbhHWORL (ORCPT ); Mon, 23 Aug 2021 10:17:11 -0400 Received: from mail-qk1-x72d.google.com (mail-qk1-x72d.google.com [IPv6:2607:f8b0:4864:20::72d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34368C061575 for ; Mon, 23 Aug 2021 07:16:29 -0700 (PDT) Received: by mail-qk1-x72d.google.com with SMTP id f22so9627599qkm.5 for ; Mon, 23 Aug 2021 07:16:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=0x0f.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=mVV/F1yIspN9pwe7wVu7K1lHM6uOf9PUbo3fvoPR78k=; b=BHe5Uy77OInHLOm4iEIYrErWvk0WVVL/wJnxS2zd9iIxsSnJJ4Ryim0bf0wwqEKv9V OusQI7ap/FQQX7GN4DV6TZtIIXJZUp1wGpr0zjIXt477qquA98U8AzCoDmmdqHyPSSQO D7rXWJDl5RSZc3OnCgag96jN0Nrmf3npWdcRo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=mVV/F1yIspN9pwe7wVu7K1lHM6uOf9PUbo3fvoPR78k=; b=R7g9vPZTZamLuO+FTwqyrV9f89vYCC2wqg7X+bcrMe5XotZz4uKzUCCIGMzf50T5ND qBVEuAhAQEDVq+kjObRb6+QZ2/+hSYAJrrX9EwWo2eAeXu4JaNlrFbIrq72rs1gtl8o/ mq6kQm3LPwU4mM4oFGVEKfQXw951hIQR6oOKLthsU75QI75F7YtLUYeWxQCRb41pPQn3 BZ2SlKOMqu18qlzUR/paRbzHV3WI817Tg7l0N4bGQV4QdL/l2eigfVD4guVgzNfo4m6p uzz70TPedVm2eLRDbpr9P+fbU4Umay7MLT97Mm4CHuH8wNdd0FksIGqGx6VlMHUOXDpc 7ocA== X-Gm-Message-State: AOAM5316l3nAE95pnJWOqPUTx3NKNwAOJpzwWZq/zXshOAHKsbZVQBeJ 8QtTjMYcuHYGzT+OyZrOXQh5fxIZvv4Zd46/FSmTs0T9XmfJzQ== X-Google-Smtp-Source: ABdhPJyWKRlQQofpj3Dewg6Zpl/82XJA0PNZcT2HQgaPxd1fZmUXKhh9E8s+3qwvLOL/tozROPLQ+SSik6PiTlAkHuE= X-Received: by 2002:a05:620a:1210:: with SMTP id u16mr21437885qkj.390.1629728188209; Mon, 23 Aug 2021 07:16:28 -0700 (PDT) MIME-Version: 1.0 References: <20210811084924.52293-1-daniel@0x0f.com> <20210816101143.2a64d7b9@xps13> In-Reply-To: <20210816101143.2a64d7b9@xps13> From: Daniel Palmer Date: Mon, 23 Aug 2021 23:19:02 +0900 Message-ID: Subject: Re: [PATCH v3] mtd: spinand: add support for Foresee FS35ND0*G parts To: Miquel Raynal Cc: linux-mtd@lists.infradead.org, richard@nod.at, Linux Kernel Mailing List , linux-arm-kernel Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Miquel, > > + /* > > + * The datasheet says *successful* with 4 bits flipped. > > + * nandbiterrs always complains that the read reported > > + * successful but the data is incorrect. > > + */ > > + case FS35ND01G_S1Y2_STATUS_ECC_4_BITFLIPS: > > + return 4; > > This is a real issue. Can you use the nandflipbits tool from the > mtd-utils package (you should take a recent version of the package) and > try to observe what happens when you insert a 4th bitflip in a section? > > I generally believe the tool more than the datasheet :) Maybe I'm using it incorrectly but I can't get a 4 bit flipped situation to happen. I erased the paged so it's all 0xFF: # flash_erase /dev/mtd0 0x8000000 1 Erasing 128 Kibyte @ 8000000 -- 100 % complete # nanddump --bb=dumpbad -s 0x8000000 -l 1 -c -p /dev/mtd0 ECC failed: 0 ECC corrected: 6234 Number of bad blocks: 0 Number of bbt blocks: 0 Block size 131072, page size 2048, OOB size 64 Dumping data starting at 0x08000000 and ending at 0x08000001... ECC: 3 corrected bitflip(s) at offset 0x08000000 0x08000000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| 0x08000010: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| 0x08000020: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| 0x08000030: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| 0x08000040: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| 0x08000050: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| 0x08000060: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| Then used nandflipbits to flip a bunch of bits in the first byte and then a few other bytes: # nanddump --bb=dumpbad -s 0x8000000 -l 1 -c -p /dev/mtd0 ECC failed: 0 ECC corrected: 6246 Number of bad blocks: 0 Number of bbt blocks: 0 Block size 131072, page size 2048, OOB size 64 Dumping data starting at 0x08000000 and ending at 0x08000001... ECC: 3 corrected bitflip(s) at offset 0x08000000 0x08000000: f0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| 0x08000010: eb ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| 0x08000020: ef ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| 0x08000030: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| 0x08000040: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| 0x08000050: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| 0x08000060: ef ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| Anyhow, I think we should probably return -EBADMSG if the 4 bit flips status appears as nandbiterrs always complains that the data is wrong. Cheers, Daniel