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 1F40BC05027 for ; Thu, 2 Feb 2023 15:00:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232746AbjBBPAN (ORCPT ); Thu, 2 Feb 2023 10:00:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39838 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232498AbjBBPAG (ORCPT ); Thu, 2 Feb 2023 10:00:06 -0500 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6096B402CF for ; Thu, 2 Feb 2023 07:00:02 -0800 (PST) Received: by mail-pj1-x1030.google.com with SMTP id j5so2136853pjn.5 for ; Thu, 02 Feb 2023 07:00:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=hjtSMcHdo/6LQulLVHOl8CPb0d7hVaersYbne3X+bik=; b=zD1E9RVv6wVZMCze1+4pkl1PKVfZrFaNrEnCtfVqtxMutX3tSn1R3IuVi8wXqBa6P4 zkHB7WD8EZJordFXOW310lBfbWLS0loyhQaRJ6GtbcTFQSuSUiH6WjThav0zun+OIEBw P4fIgWFFWP1gxlgS/Zgouibh4BGlxtBcI94SM/T7TEjdyfB2KyPPeA3iseJAVpIFdP6D iClQL/jWN05/4EayDiAEXERg3PdellksQkzqpSzHLnuFPOGMixExvAE2MjIJ4rOPqfuF KKPMa4p8jy/9VjI5YRF6hwbkBRK6khrRF+sIpnaGaGcBr3pDvPRz75Oaqi5SNzAFJSWN TmBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=hjtSMcHdo/6LQulLVHOl8CPb0d7hVaersYbne3X+bik=; b=6XUK/bcFjKHN9JhXrEl8Lv+AfDx0Y1TQi4Y6Ev5MHdltlCBsKfl2O0jKBXhzkvgcfp l2u3PCU/EmhKdBZpe9tdzbw36SmsPtR/HxB/gzzNZmdPByfpQ00iBqrZyVTFZITEmBSr Cnos9GZUUHu114juGKDoMeh9LtoGWAKkkff2gMznUUSU+vbDHk2ffKyEK2NstU5s8lXt k6lzJiiI/H9c5lFlKC7LJRBk2tbIj1ZB+zuK5y+KuH9gfktyS5qkKnWPd7ygglnYMUGO QJxGtkxdhA3js7lt8ZzeebyYlTca048XTTYmQQjHzWHG4e3U+qt/pWl1PG/BE8AbwSLx 4gwQ== X-Gm-Message-State: AO0yUKW45Gj2BnJPz/vnYWqBqkZG3kzkEPrSoOp4Bkr7M1RLKho+lU+y Hm5w+3ni8ptMzTIp2GvpOPCaglqk+262/V29Hg1HAA== X-Google-Smtp-Source: AK7set9YKduFWnTdTRlctnFptPfKDcEe5mltzTPrSDe8AB+1hnqam2H1UBHfk2HaxsG9DmoA9IT8Hmk2x9+IrlfWkjs= X-Received: by 2002:a17:902:e807:b0:198:a084:faa9 with SMTP id u7-20020a170902e80700b00198a084faa9mr1529979plg.33.1675350001791; Thu, 02 Feb 2023 07:00:01 -0800 (PST) MIME-Version: 1.0 References: <20230129023630.830764-1-chenhuiz@axis.com> In-Reply-To: From: Ulf Hansson Date: Thu, 2 Feb 2023 15:59:25 +0100 Message-ID: Subject: Re: [PATCH] dt-bindings: mmc: Add cap-aggressive-pm property To: Hermes Zhang , Krzysztof Kozlowski Cc: Rob Herring , Krzysztof Kozlowski , kernel@axis.com, linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 31 Jan 2023 at 17:57, Krzysztof Kozlowski wrote: > > On 30/01/2023 07:54, Hermes Zhang wrote: > > On 2023/1/29 18:58, Krzysztof Kozlowski wrote: > >> On 29/01/2023 03:36, Hermes Zhang wrote: > >>> This commit add a new property: cap-aggressive-pm to enable the > >> Do not use "This commit/patch". > >> https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95 > > > > Done > > > >>> MMC_CAP_AGGRESSIVE_PM feature for (e)MMC/SD power saving. > >> Why this is a property suitable for DT? IOW, why this isn't enabled always? > > > > This property will benfit for the power consumption, but it also may > > degradation in performance as it will prevent the > > > > the card from executing internal house-keeping operations in idle mode. > > So it's better to config it from DT. > > Why? DT is not for policy. How you described it, this is policy or > system tuning choice thus the job for Linux (OS), not for DT. So I will > repeat - why this property fits the purpose of DT (describe the hardware). > I guess the HW perspective here, is that it might not fit all platforms nor the actual eMMC/SD card to support this feature. However, it still seems like a policy rather than a strict HW constraint. Perhaps there is a way to figure out in the host driver, to conditionally set the MMC_CAP_AGGRESSIVE_PM for the host, when needed instead? Kind regards Uffe