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=-10.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 3B0EEC4363D for ; Mon, 5 Oct 2020 09:38:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E93452078E for ; Mon, 5 Oct 2020 09:38:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Pgk0M12g" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725919AbgJEJiY (ORCPT ); Mon, 5 Oct 2020 05:38:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725917AbgJEJiY (ORCPT ); Mon, 5 Oct 2020 05:38:24 -0400 Received: from mail-lf1-x142.google.com (mail-lf1-x142.google.com [IPv6:2a00:1450:4864:20::142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A415C0613CE; Mon, 5 Oct 2020 02:38:24 -0700 (PDT) Received: by mail-lf1-x142.google.com with SMTP id y2so10015533lfy.10; Mon, 05 Oct 2020 02:38:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=QsaBfZFa2dvXngI+qikBeYVIehcnUn/8wXHfmURCQEA=; b=Pgk0M12g2DtRJ1kAa1PGSelgbsxYQlS2lso0eKSxlD4N1cVf5e20H+glqExrxAqrUI 9Nf6vAtoA4YEhEfnQnopMNWK72mArJ5RrpqbeYqVmC6P3cX5k744sYEV/PS5FqaLm7OA +wiU38Q3ioB+Hm6EiKqGBN9sGquqVgdGhu4XY7IEDQE6DZnfkat7Pt7hrcf+7xAJet9n MlATvl5Cj2DSe+EVz0BzED9ODORqqYSsjRWGTATd2sLePQt+qYY4A14HXi1mX07cXfrL umwgYoAWFk7Nm+x7gWS7G8Z2sS/3sxzTuNxWDEu1qQNknleKhir7JYA2xNJNWoXbxVID uCqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=QsaBfZFa2dvXngI+qikBeYVIehcnUn/8wXHfmURCQEA=; b=rtayqCpsNSgLmYo3+73qSPPETv/f50j7/AnN+qlne0qtDsVoCiAi8B5cxVtSi7nTtL c/nLuXje/xOMNe3KCy8MCFm1zMrt1eBGPd+cufqS/rtDh/FElTfVGmi1mvHfQNHCp/47 96+/TApwJaUpUAEM/HAB739IOuE2Uh8DYSwWf+AoIBi3g0MOk2wBzH/7kmG0cLIX7s/K j5Wbx/ivX3p2uM8atdg2U3vUmRMSHXN0XTGX3YIB2MaFX09ra7P2R9ciW75oNXe6S+Ig WNqcNuYsaEjPubnC80QO/LYVX2D1b379pCbSJDImZ0VgUCAurBksbvHD5xx9YvVINsvM +YTw== X-Gm-Message-State: AOAM531xAXWXtGVVKl2H4lLjtvYXjGYkWDR0Dvwas19V1UWVf9NZtWMi D6Xfks6+zg0vonc2UP/BrCLZGx3n8N4= X-Google-Smtp-Source: ABdhPJw9nOUB2K6tl/E249a5ebviDASlcj91s9oVh68i6PWqDc7YsQuI0RDXL8DV8yyicewQ2Gaj0w== X-Received: by 2002:ac2:4c88:: with SMTP id d8mr5071687lfl.428.1601890702324; Mon, 05 Oct 2020 02:38:22 -0700 (PDT) Received: from [192.168.2.145] ([109.252.91.252]) by smtp.googlemail.com with ESMTPSA id n3sm2627012lfq.274.2020.10.05.02.38.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 05 Oct 2020 02:38:21 -0700 (PDT) Subject: Re: [PATCH v3 2/3] iommu/tegra-smmu: Rework .probe_device and .attach_dev To: Thierry Reding Cc: Nicolin Chen , joro@8bytes.org, krzk@kernel.org, vdumpa@nvidia.com, jonathanh@nvidia.com, linux-tegra@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org References: <20200930084258.25493-1-nicoleotsuka@gmail.com> <20200930084258.25493-3-nicoleotsuka@gmail.com> <20200930153131.GB3833404@ulmo> <20200930160626.GD3833404@ulmo> <20200930164707.GB3852280@ulmo> <35115ac1-fb25-7226-7b50-61193669e696@gmail.com> <20201001075811.GA3919720@ulmo> <4dbf5bcb-76af-53c5-31cf-880debbcebf3@gmail.com> <20201005091610.GC425362@ulmo> From: Dmitry Osipenko Message-ID: <1adede6e-ecbd-eea4-bd40-4969cd8719cc@gmail.com> Date: Mon, 5 Oct 2020 12:38:20 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201005091610.GC425362@ulmo> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org 05.10.2020 12:16, Thierry Reding пишет: ... >> I think you meant regmap in regards to protecting IO accesses, but this >> is not what regmap is about if IO accesses are atomic by nature. > > Then why is there regmap-mmio? To protect programming sequences for example, actually that's the only real use-case I saw in kernel drivers once. In our case there are no sequences that require protection, at least I'm not aware about that. >> Secondly, you're missing that tegra30-devfreq driver will also need to >> perform the MC lookup [3] and then driver will no longer work for the >> older DTs if phandle becomes mandatory because these DTs do not have the >> MC phandle in the ACTMON node. >> >> [3] >> https://github.com/grate-driver/linux/commit/441d19281f9b3428a4db1ecb3a02e1ec02a8ad7f >> >> So we will need the fall back for T30/124 as well. > > No, we don't need the fallback because this is new functionality which > can and should be gated on the existence of the new phandle. If there's > no phandle then we have no choice but to use the old code to ensure old > behaviour. You just repeated what I was trying to say:) Perhaps I spent a bit too much time touching that code to the point that lost feeling that there is a need to clarify everything in details. 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Mon, 05 Oct 2020 02:38:21 -0700 (PDT) Subject: Re: [PATCH v3 2/3] iommu/tegra-smmu: Rework .probe_device and .attach_dev To: Thierry Reding References: <20200930084258.25493-1-nicoleotsuka@gmail.com> <20200930084258.25493-3-nicoleotsuka@gmail.com> <20200930153131.GB3833404@ulmo> <20200930160626.GD3833404@ulmo> <20200930164707.GB3852280@ulmo> <35115ac1-fb25-7226-7b50-61193669e696@gmail.com> <20201001075811.GA3919720@ulmo> <4dbf5bcb-76af-53c5-31cf-880debbcebf3@gmail.com> <20201005091610.GC425362@ulmo> From: Dmitry Osipenko Message-ID: <1adede6e-ecbd-eea4-bd40-4969cd8719cc@gmail.com> Date: Mon, 5 Oct 2020 12:38:20 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201005091610.GC425362@ulmo> Content-Language: en-US Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, krzk@kernel.org, jonathanh@nvidia.com, linux-tegra@vger.kernel.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; 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