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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 E2E9BC3A59E for ; Sat, 24 Aug 2019 11:03:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF33620673 for ; Sat, 24 Aug 2019 11:03:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727976AbfHXLDf convert rfc822-to-8bit (ORCPT ); Sat, 24 Aug 2019 07:03:35 -0400 Received: from relay8-d.mail.gandi.net ([217.70.183.201]:37583 "EHLO relay8-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727795AbfHXLDf (ORCPT ); Sat, 24 Aug 2019 07:03:35 -0400 X-Originating-IP: 91.224.148.103 Received: from xps13 (unknown [91.224.148.103]) (Authenticated sender: miquel.raynal@bootlin.com) by relay8-d.mail.gandi.net (Postfix) with ESMTPSA id F1F5D1BF206; Sat, 24 Aug 2019 11:03:30 +0000 (UTC) Date: Sat, 24 Aug 2019 13:03:29 +0200 From: Miquel Raynal To: Mason Yang Cc: richard@nod.at, marek.vasut@gmail.com, dwmw2@infradead.org, bbrezillon@kernel.org, computersforpeace@gmail.com, vigneshr@ti.com, kstewart@linuxfoundation.org, juliensu@mxic.com.tw, linux-kernel@vger.kernel.org, frieder.schrempf@kontron.de, linux-mtd@lists.infradead.org, tglx@linutronix.de Subject: Re: [PATCH] Add support for Macronix NAND randomizer Message-ID: <20190824130329.68f310aa@xps13> In-Reply-To: <1566280428-4159-1-git-send-email-masonccyang@mxic.com.tw> References: <1566280428-4159-1-git-send-email-masonccyang@mxic.com.tw> Organization: Bootlin X-Mailer: Claws Mail 3.17.3 (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 Mason, Mason Yang wrote on Tue, 20 Aug 2019 13:53:48 +0800: > Macronix NANDs support randomizer operation for user data scrambled, > which can be enabled with a SET_FEATURE. > > User data written to the NAND device without randomizer is still readable > after randomizer function enabled. > The penalty of randomizer are NOP = 1 instead of NOP = 4 and more time period please don't use 'NOP' here, use 'subpage accesses' instead, otherwise people might not understand what it means while it has a real impact. > is needed in program operation and entering deep power-down mode. > i.e., tPROG 300us to 340us(randomizer enabled) > > If subpage write not available with hardware ECC, for example, > NAND chip options NAND_NO_SUBPAGE_WRITE be set in driver and > randomizer function is recommended for high-reliability. > Driver checks byte 167 of Vendor Blocks in ONFI parameter page table > to see if this high-reliability function is supported. > You did not flagged this patch as a v2 and forgot about the changelog. You did not listen to our comments in the last version neither. I was open to a solution with a specific DT property for warned users but I don't see it coming. Thanks, Miquèl