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=-17.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 A0DBFC2B9F7 for ; Wed, 26 May 2021 10:01:06 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6F6FF613B5 for ; Wed, 26 May 2021 10:01:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6F6FF613B5 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-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=2GKvuwDMtnrMFOEj24xJV85inA4g2TiZ6R8IZHM7HX4=; b=TR3d9TXwdVVcS1 PttOZNuHcW5pJrYsHwymWil3IdjxPuu0G28gZTtOQNIlKlklbqBEkacd9Xkq8IiTtW8hu4EkBiQDQ DjMu+UKMQNlAJBNfW3jxNKZL4ABkSw3UIMnLL9P9lIClROhbadNvcBIBgXNQ8kPFHBNYsQFac7mcn l3TniadT3xF9LO1F7hDvJNTtjOUi/3aqiK2eDdwI1j2zpJo91Q+Ia2XIYl3uQtISfupuaX0T64MDx 8pV5cZqEtebAnxoTimlkDNwuDc3D6HP7CsWRpny8w77nGT4d92x4KxNB5xJy66DTljlfOLXWky2u4 EQ0a8DmxgCuGtjHTZQhg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1llqKv-00D3XI-0S; Wed, 26 May 2021 10:00:25 +0000 Received: from relay9-d.mail.gandi.net ([217.70.183.199]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1llpSU-00CiND-JR for linux-mtd@lists.infradead.org; Wed, 26 May 2021 09:04:12 +0000 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay9-d.mail.gandi.net (Postfix) with ESMTPSA id D8515FF80C; Wed, 26 May 2021 09:04:07 +0000 (UTC) From: Miquel Raynal To: Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Tudor Ambarus , linux-mtd@lists.infradead.org Cc: Thomas Petazzoni , Michal Simek , Naga Sureshkumar Relli , Amit Kumar Mahapatra Subject: Re: [PATCH 18/22] mtd: rawnand: Choose the best timings, NV-DDR included Date: Wed, 26 May 2021 11:04:07 +0200 Message-Id: <20210526090407.181615-1-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210505213750.257417-19-miquel.raynal@bootlin.com> References: MIME-Version: 1.0 X-linux-mtd-patch-notification: thanks X-linux-mtd-patch-commit: b'a9ecc8c814e9600836e00cb592f1cb5378393126' X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210526_020410_812786_FD632306 X-CRM114-Status: GOOD ( 16.63 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org On Wed, 2021-05-05 at 21:37:46 UTC, Miquel Raynal wrote: > Now that the necessary peaces to support the NV-DDR interface type have > been contributed, let's add the relevant logic to make use of it. In > particular, the core does not choose the best SDR timings anymore but > calls a more generic helper instead. > > This helper checks if NV-DDR is supported by trying to find the best > NV-DDR supported mode through a logic very close to what is being done > for SDR timings. If no NV-DDR mode in common between the NAND controller > and the NAND chip is found, the core will fallback to SDR. > > Side note: theoretically, the data clock speed in NV-DDR mode 0 is > slower than in SDR mode 5. In the situation where we would get a working > NV-DDR mode 0, we could also try if SDR mode 5 is supported and > eventually fallback to it in order to get the fastest possible > throughput. However, in the field, it looks like most of the devices > supporting NV-DDR avoid implementing the fastest SDR modes (like 4 and 5 > EDO modes, which are a bit more complicated to handle than the other SDR > modes). So, we will stick to the simplest logic: try NV-DDR otherwise > fallback to SDR. If someone else experiences strong differences because > of that we may still implement the logic defined above. > > Signed-off-by: Miquel Raynal Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git nand/next. Miquel ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/