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 4AACFC76195 for ; Tue, 28 Mar 2023 10:23:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230330AbjC1KXY (ORCPT ); Tue, 28 Mar 2023 06:23:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58638 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230156AbjC1KXW (ORCPT ); Tue, 28 Mar 2023 06:23:22 -0400 Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [IPv6:2a00:1450:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 39A7A618A for ; Tue, 28 Mar 2023 03:23:21 -0700 (PDT) Received: by mail-wm1-x32a.google.com with SMTP id l37so6612742wms.2 for ; Tue, 28 Mar 2023 03:23:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1679998999; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=JDzRFYi3RNic/LekPtwT66dQgjxUn0+xUq4SVUW3hGI=; b=qXrZqxXvk8TTChUZvPxCud+eZ30VRquAfpJfwKULgIKukYnNsDRVWrskBs/yGah/3i 83B3/EjSGl4dG+VgHadyDwYoaC1hi4MbOvy1Qc2Oc/+DqWQeR6+s8D9LmVi0xWDmAs8H LMZutayy8YOQjc8VKeUcs0yO0SsYc03T+45tfadMHO7MRoueM/QsyW0yovgBLvdvelyo Qwiz7IJJJbiRlBCKJUuCd/ag5c5rgNiYpFUfixZnpvZhNmtRM49t0A2pQLYaRAzjvwh6 lRTG3xl22rAxnQ0SIPzcP5Zrc+6LVD6klcI3ntmHYlyR/vxfVCA6z+9fLOxL5LFDZLEt Lc1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679998999; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=JDzRFYi3RNic/LekPtwT66dQgjxUn0+xUq4SVUW3hGI=; b=m/KsWDIL6m+8stupyp+6a5cCoenZmt1TGa9a7H1MtpYRR5uVe9Ey06ADDtOIYtIeiE PMDYz/CjIVid/vZmHaUlxKSIAP00NJch1SLPmTOapSmT3gCsHA5FX8bJOZnae5gVtFc6 rWAL4l9zwyi7ve4c1IveLeZjRagvmth5NZozSHPMdW1YWQjSzn1Z6409216B+VPl55Vb 7i81IbR3lGriGsAnBCkal8zCuMXaSk+GvqDklituqs/zj45AMNYPEoNcAvz8IB4fkCbI Wmgog5SH3qgnCPBy/idzgzOIWp9eGMqkQcJ62M+/YKxDkGxhRGLoTR8VgHhxLi0Y4S7y SEuQ== X-Gm-Message-State: AO0yUKV/KrJ6Sdrsj+LZat7X7iTCXWAkM7Gi1E6Xo9M0iQdWhn579bgv PesRlg0VSAsB1xDRFrKF1Wxlew== X-Google-Smtp-Source: AK7set8+rVt9uMI2B65S9+dtPSt7AljkPiJbA/L6F0xN8a1/8VPJfc6C35dLQrNoKrs8jVWLcThGVQ== X-Received: by 2002:a05:600c:291:b0:3ee:5147:3acd with SMTP id 17-20020a05600c029100b003ee51473acdmr11510334wmk.40.1679998999667; Tue, 28 Mar 2023 03:23:19 -0700 (PDT) Received: from [192.168.2.107] ([79.115.63.91]) by smtp.gmail.com with ESMTPSA id u17-20020a05600c19d100b003ef5e5f93f5sm11981393wmq.19.2023.03.28.03.23.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 28 Mar 2023 03:23:19 -0700 (PDT) Message-ID: <026b9d7d-86db-45cd-9e86-066fa826a77e@linaro.org> Date: Tue, 28 Mar 2023 11:23:18 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1 Subject: Re: [PATCH v3 1/4] ARM: dts: at91-sama5d27_wlsom1: Set sst26vf064b SPI NOR flash at its maximum frequency Content-Language: en-US To: nicolas.ferre@microchip.com, claudiu.beznea@microchip.com Cc: alexandre.belloni@bootlin.com, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Tudor Ambarus References: <20230328101517.1595738-1-tudor.ambarus@linaro.org> <20230328101517.1595738-2-tudor.ambarus@linaro.org> From: Tudor Ambarus In-Reply-To: <20230328101517.1595738-2-tudor.ambarus@linaro.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 3/28/23 11:15, Tudor Ambarus wrote: > From: Tudor Ambarus > cut > Signed-off-by: Tudor Ambarus I don't understand why these differ. On my local machine I see them match: commit e208a7b04cbde950588c561889d2f8eb8a10485f Author: Tudor Ambarus Date: Thu Nov 17 12:52:46 2022 +0200 ARM: dts: at91-sama5d27_wlsom1: Set sst26vf064b SPI NOR flash at its maximum frequency sama5d27-wlsom1 populates an sst26vf064b SPI NOR flash. Its maximum operating frequency for 2.7-3.6V is 104 MHz. As the flash is operated at 3.3V, increase its maximum supported frequency to 104MHz. The increasing of the spi-max-frequency value requires the setting of the "CE# Not Active Hold Time", thus set the spi-cs-setup-ns to a value of 7. The sst26vf064b datasheet specifies just a minimum value for the "CE# Not Active Hold Time" and it advertises it to 5 ns. There's no maximum time specified. I determined experimentally that 5 ns for the spi-cs-setup-ns is not enough when the flash is operated close to its maximum frequency and tests showed that 7 ns is just fine, so set the spi-cs-setup-ns dt property to 7. With the increase of frequency the reads are now faster with ~37%. Signed-off-by: Tudor Ambarus Anyway, you can keep v2 then, looks like v2 has the same email on both the author line and the S-o-b line. It's fine by me even if it is with @microchip.com: https://lore.kernel.org/all/20230328100723.1593864-2-tudor.ambarus@linaro.org/