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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 54104C43387 for ; Mon, 17 Dec 2018 16:41:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2A3882133F for ; Mon, 17 Dec 2018 16:41:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388324AbeLQQl1 convert rfc822-to-8bit (ORCPT ); Mon, 17 Dec 2018 11:41:27 -0500 Received: from mail.bootlin.com ([62.4.15.54]:32896 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388223AbeLQQl0 (ORCPT ); Mon, 17 Dec 2018 11:41:26 -0500 Received: by mail.bootlin.com (Postfix, from userid 110) id 5ADF4207B2; Mon, 17 Dec 2018 17:41:24 +0100 (CET) Received: from xps13 (aaubervilliers-681-1-89-7.w90-88.abo.wanadoo.fr [90.88.30.7]) by mail.bootlin.com (Postfix) with ESMTPSA id 0601420723; Mon, 17 Dec 2018 17:41:13 +0100 (CET) Date: Mon, 17 Dec 2018 17:41:14 +0100 From: Miquel Raynal To: Naga Sureshkumar Relli Cc: Boris Brezillon , "robh@kernel.org" , "richard@nod.at" , "linux-kernel@vger.kernel.org" , "marek.vasut@gmail.com" , "linux-mtd@lists.infradead.org" , "nagasuresh12@gmail.com" , Michal Simek , "computersforpeace@gmail.com" , "dwmw2@infradead.org" Subject: Re: [LINUX PATCH v12 3/3] mtd: rawnand: arasan: Add support for Arasan NAND Flash Controller Message-ID: <20181217174114.24196d17@xps13> In-Reply-To: References: <1541739641-17789-1-git-send-email-naga.sureshkumar.relli@xilinx.com> <20181118204324.373ca9cc@bbrezillon> <20181119090246.49060019@bbrezillon> <20181120120244.7d2442b5@bbrezillon> <20181120133624.3fa4742d@xps13> <20181212091135.1d0cc9a6@xps13> <20181212100931.149b0cac@xps13> <20181212141825.69711c57@xps13> 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 Naga, [...] > Inserted biterror @ 48/7 > Successfully corrected 25 bit errors per subpage > Inserted biterror @ 50/7 > ECC failure, invalid data despite read success > root@xilinx-zc1751-dc2-2018_1:~# > > But even in this case also, driver is saying ECC failure but read success. > That means controller is able to detect errors on read page up to 24 bit only. > After that there is no way to say to the upper layers that the page is bad because of the limitation in the controller. This is more than a "limitation", the design is broken. I am not sure how to support such controller, and I am not sure if we even want to. > Could you please suggest any alternative to report the errors in that case? Shall we support the controller without the hw ECC engine? Boris, any thoughts? Thanks, Miquèl