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=-5.6 required=3.0 tests=DATE_IN_PAST_06_12, DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 85D0CC76194 for ; Thu, 25 Jul 2019 05:47:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5FF4D2075C for ; Thu, 25 Jul 2019 05:47:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564033650; bh=7h3xjwCuMzG9QgcuPlQaEu4Qk7po7mY7FzUvG8n8IzQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PHHVIcNtUXnTz1+6ndNO4DMXuWUTeYTNuabX7l4AxO0YRYX+gWowESSi6BDkU/WiL MP5v9Aqachh00FLoHmqX3ZkZ/a4x2KGteJvPbZhq9e6H8Dnx/ExnbM20I2Rej0rHW1 dBNjBj+zalI+HiUovLyqilTRa+RigO3LW4fznG7M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387567AbfGYFrY (ORCPT ); Thu, 25 Jul 2019 01:47:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:35320 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387580AbfGYFrV (ORCPT ); Thu, 25 Jul 2019 01:47:21 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C3E932075C; Thu, 25 Jul 2019 05:47:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564033640; bh=7h3xjwCuMzG9QgcuPlQaEu4Qk7po7mY7FzUvG8n8IzQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ejf6VJkJi0iRRTcI3XWH+jhxOUzKAufMRdfEPjhZE2vw6PYUrYudlCLjTFkbzISSl iMAMqanGazazr+HHwWU065qAtNowsWBZHz4KdhFA7nlUF2dfKVTssKMEcxElo+odY2 uZlnM8xFyLwpKaHcvu8YjXf+QAl+2H2ihUy4pvAI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiaolei Li , Miquel Raynal Subject: [PATCH 4.19 261/271] mtd: rawnand: mtk: Correct low level time calculation of r/w cycle Date: Wed, 24 Jul 2019 21:22:10 +0200 Message-Id: <20190724191717.570128067@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190724191655.268628197@linuxfoundation.org> References: <20190724191655.268628197@linuxfoundation.org> User-Agent: quilt/0.66 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 From: Xiaolei Li commit e1884ffddacc0424d7e785e6f8087bd12f7196db upstream. At present, the flow of calculating AC timing of read/write cycle in SDR mode is that: At first, calculate high hold time which is valid for both read and write cycle using the max value between tREH_min and tWH_min. Secondly, calculate WE# pulse width using tWP_min. Thridly, calculate RE# pulse width using the bigger one between tREA_max and tRP_min. But NAND SPEC shows that Controller should also meet write/read cycle time. That is write cycle time should be more than tWC_min and read cycle should be more than tRC_min. Obviously, we do not achieve that now. This patch corrects the low level time calculation to meet minimum read/write cycle time required. After getting the high hold time, WE# low level time will be promised to meet tWP_min and tWC_min requirement, and RE# low level time will be promised to meet tREA_max, tRP_min and tRC_min requirement. Fixes: edfee3619c49 ("mtd: nand: mtk: add ->setup_data_interface() hook") Cc: stable@vger.kernel.org # v4.17+ Signed-off-by: Xiaolei Li Reviewed-by: Miquel Raynal Signed-off-by: Miquel Raynal Signed-off-by: Greg Kroah-Hartman --- drivers/mtd/nand/raw/mtk_nand.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) --- a/drivers/mtd/nand/raw/mtk_nand.c +++ b/drivers/mtd/nand/raw/mtk_nand.c @@ -509,7 +509,8 @@ static int mtk_nfc_setup_data_interface( { struct mtk_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd)); const struct nand_sdr_timings *timings; - u32 rate, tpoecs, tprecs, tc2r, tw2r, twh, twst, trlt; + u32 rate, tpoecs, tprecs, tc2r, tw2r, twh, twst = 0, trlt = 0; + u32 thold; timings = nand_get_sdr_timings(conf); if (IS_ERR(timings)) @@ -545,11 +546,28 @@ static int mtk_nfc_setup_data_interface( twh = DIV_ROUND_UP(twh * rate, 1000000) - 1; twh &= 0xf; - twst = timings->tWP_min / 1000; + /* Calculate real WE#/RE# hold time in nanosecond */ + thold = (twh + 1) * 1000000 / rate; + /* nanosecond to picosecond */ + thold *= 1000; + + /* + * WE# low level time should be expaned to meet WE# pulse time + * and WE# cycle time at the same time. + */ + if (thold < timings->tWC_min) + twst = timings->tWC_min - thold; + twst = max(timings->tWP_min, twst) / 1000; twst = DIV_ROUND_UP(twst * rate, 1000000) - 1; twst &= 0xf; - trlt = max(timings->tREA_max, timings->tRP_min) / 1000; + /* + * RE# low level time should be expaned to meet RE# pulse time, + * RE# access time and RE# cycle time at the same time. + */ + if (thold < timings->tRC_min) + trlt = timings->tRC_min - thold; + trlt = max3(trlt, timings->tREA_max, timings->tRP_min) / 1000; trlt = DIV_ROUND_UP(trlt * rate, 1000000) - 1; trlt &= 0xf;