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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 56003C433EF for ; Fri, 3 Jun 2022 14:34:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245104AbiFCOeV (ORCPT ); Fri, 3 Jun 2022 10:34:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54838 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244009AbiFCOeV (ORCPT ); Fri, 3 Jun 2022 10:34:21 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C551A5045E; Fri, 3 Jun 2022 07:34:18 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 52E86616F9; Fri, 3 Jun 2022 14:34:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7BDC3C385A9; Fri, 3 Jun 2022 14:34:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1654266857; bh=3nAELPzfAqOQmMeq44MqN+8FRP1GoZ6OQ7z/q+8F6nE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XH0DMFMPOaK4wqwPXozOLeoRU+BC9lC/4jjMf8Ss8jxwAImkqjIqfZy5jOSObMEw3 MktfV//vAQ0NbofATGFbRO5O8D3bJG/J06Ainax6o3NAaAEHHLonj5OCDp7DuODnbs 1VKxKZ6rChwetbrDOF80MsnQZsG4gGnYnjBOzPzn8GTeEZVj8iX1sTgZRx61sjsFbU IIGG/yCeqP9fDpRIlgv3PPVT5oT9gPYI/gfSE1Nkac3pTOl74HzozkA3u4dSRyoXsw fi76rV1bOrhDcp1TwwVq62G5W0QVSQA5aCuCW+7nEwufMxI3m3AkvRCIdacVXBk6bf SFGf3+R3I32Pw== Date: Fri, 3 Jun 2022 20:04:10 +0530 From: Manivannan Sadhasivam To: Miquel Raynal Cc: Ansuel Smith , Andy Gross , Bjorn Andersson , Richard Weinberger , Vignesh Raghavendra , Rob Herring , Krzysztof Kozlowski , linux-mtd@lists.infradead.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 0/2] Add support for unprotected spare data page Message-ID: <20220603143410.GA26696@thinkpad> References: <20220519190112.6344-1-ansuelsmth@gmail.com> <20220603154934.521c57ab@xps-13> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220603154934.521c57ab@xps-13> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Fri, Jun 03, 2022 at 03:49:34PM +0200, Miquel Raynal wrote: > Hi, > > ansuelsmth@gmail.com wrote on Thu, 19 May 2022 21:01:10 +0200: > > > Some background about this. > > On original qsdk ipq8064 based firmware there was a big separation from > > boot partition and user partition. With boot partition we refer to > > partition used to init the router (bootloader, spm firmware and other > > internal stuff) With user partition we refer to linux partition and data > > partition not used to init the router. > > When someone had to write to these boot partition a special mode was > > needed, to switch the nand driver to this special configuration. > > > > Upstream version of the nandc driver totally dropped this and the result > > is that if someone try to read data from these partition a CRC warning > > is printed and if someone try to write that (if for example someone > > wants to replace the bootloader) result is a broken system as the data > > is badly written. > > > > This series comes to fix this. > > > > A user can declare offset and size of these special partition using the > > qcom,boot-pages binding. > > > > An initial implementation of this assumed that the boot-pages started > > from the start of the nand but we discover that some device have backup > > of these special partition and we can have situation where we have this > > partition scheme > > - APPSBL (require special mode) > > - APPSBLENV (doesn't require special mode) > > - ART > > - APPSBLBK (back of APPSBL require special mode) > > - APPSBLENVBK (back of APPSBLENV doesn't require special mode) > > With this configuration we need to declare sparse boot page and we can't > > assume boot-pages always starts from the start of the nand. > > > > A user can use this form to declare sparse boot pages > > qcom,boot-pages = <0x0 0x0c80000 0x0c80000 0x0500000>; > > > > The driver internally will parse this array, convert it to nand pages > > and check internally on every read/write if this special configuration > > should used for that page or the normal one. > > > > The reason for all of this is that qcom FOR SOME REASON, disable ECC for > > spare data only for these boot partition and we need to reflect this > > special configuration to mute these warning and to permit actually > > writing to these pages. > > Manivannan, any feedback on this? > Sorry for the delay. I will check internally on some of the unknown implementations mentioned and provide my comments. Thanks, Mani > > > > v4: > > - Fix wrong compatible set for boot-pages (ipq8074 instead of ipq806x) > > v3: > > - Fix typo in Docmunetation commit desription > > - Add items description for uint32-matrix > > v2: > > - Add fixes from Krzysztof in Documentation > > > > Ansuel Smith (2): > > mtd: nand: raw: qcom_nandc: add support for unprotected spare data > > pages > > dt-bindings: mtd: qcom_nandc: document qcom,boot-pages binding > > > > .../devicetree/bindings/mtd/qcom,nandc.yaml | 26 +++ > > drivers/mtd/nand/raw/qcom_nandc.c | 148 +++++++++++++++++- > > 2 files changed, 169 insertions(+), 5 deletions(-) > > > > Thanks, > Miquèl -- மணிவண்ணன் சதாசிவம்