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=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 D8223C433DB for ; Tue, 9 Feb 2021 23:37:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A665864DF5 for ; Tue, 9 Feb 2021 23:37:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234319AbhBIXgW (ORCPT ); Tue, 9 Feb 2021 18:36:22 -0500 Received: from mail-ot1-f43.google.com ([209.85.210.43]:45276 "EHLO mail-ot1-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234536AbhBIW5l (ORCPT ); Tue, 9 Feb 2021 17:57:41 -0500 Received: by mail-ot1-f43.google.com with SMTP id o12so40142ote.12 for ; Tue, 09 Feb 2021 14:57:23 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=chF4AGWod1NaZkKppPWEQ1Io26jYw+8zMgU0N2aN71E=; b=H/7kroK1cffempLli8FSrZ1g6MttNwGabYtTgWSQ4UobXuWEs5gq/jA4qcqRwP6iRc S5eopn3XhxSLq/882YST3XRnfCIWmfQmwH/EXs8jwtPT+c+ArV03vJTi1wJicG+u64zv 6h8QJj2XvcxGC2+0dhEHlK33zPvYIADaIU2wCvEO50r5gPbli9T5rabSBFRlKIpCGvPO Dapk38XN5E8vVXSXeJLVQHb6l3x5YIRC/m79dDWhkAx3/e2UO5QwF8UTkmXoD68LG89A 5elfwnqFqskUvXxyBiA4FPg9G8OUKUhzHH1ghPu24whLwqgSd67bgrkPbgTWKKN3BRxn zN2w== X-Gm-Message-State: AOAM530k4yqXgl7dfakN18dS6o8Kt1pKZnoa0+5OjSEOp7At511nNUAy mp4ruLd9E8m7Hh2PZp2yg2s+D/ZryQ== X-Google-Smtp-Source: ABdhPJyGu3u5I/yz8BcR5c4Z5Un368IPwJTe9EIJ9SQLRz14qAclf658hUeQwMCs2kjkfjj8BHycEw== X-Received: by 2002:a9d:21ca:: with SMTP id s68mr17271906otb.164.1612906403390; Tue, 09 Feb 2021 13:33:23 -0800 (PST) Received: from robh.at.kernel.org (24-155-109-49.dyn.grandenetworks.net. [24.155.109.49]) by smtp.gmail.com with ESMTPSA id o83sm418383ooo.37.2021.02.09.13.33.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Feb 2021 13:33:22 -0800 (PST) Received: (nullmailer pid 232145 invoked by uid 1000); Tue, 09 Feb 2021 21:33:20 -0000 Date: Tue, 9 Feb 2021 15:33:20 -0600 From: Rob Herring To: Saravana Kannan Cc: Jonathan Corbet , Greg Kroah-Hartman , "Rafael J. Wysocki" , Kevin Hilman , Ulf Hansson , Len Brown , Len Brown , Pavel Machek , Michael Turquette , Stephen Boyd , Frank Rowand , Marc Zyngier , Thomas Gleixner , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-clk@vger.kernel.org, devicetree@vger.kernel.org, linux-acpi@vger.kernel.org, Marek Szyprowski , Geert Uytterhoeven , kernel-team@android.com Subject: Re: [PATCH v4 4/8] of: property: Add fw_devlink support for optional properties Message-ID: <20210209213320.GA219007@robh.at.kernel.org> References: <20210205222644.2357303-1-saravanak@google.com> <20210205222644.2357303-5-saravanak@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210205222644.2357303-5-saravanak@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Fri, Feb 05, 2021 at 02:26:40PM -0800, Saravana Kannan wrote: > Not all DT bindings are mandatory bindings. Add support for optional DT > bindings and mark iommus, iommu-map, dmas as optional DT bindings. I don't think we can say these are optional or not. It's got to be a driver decision somehow. For example, if IOMMU is optional, what happens with this sequence: driver probes without IOMMU driver calls dma_map_?() IOMMU driver probes h/w accesses DMA buffer --> BOOM!