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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 6567DC5CFE7 for ; Wed, 11 Jul 2018 18:04:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2981720C0D for ; Wed, 11 Jul 2018 18:04:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2981720C0D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732381AbeGKSJ0 (ORCPT ); Wed, 11 Jul 2018 14:09:26 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:41296 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726395AbeGKSJ0 (ORCPT ); Wed, 11 Jul 2018 14:09:26 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 680E580D; Wed, 11 Jul 2018 11:03:58 -0700 (PDT) Received: from [10.1.210.23] (e110467-lin.cambridge.arm.com [10.1.210.23]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9A7A53F589; Wed, 11 Jul 2018 11:03:56 -0700 (PDT) Subject: Re: [RFC PATCH 2/4] ACPI/IORT: Set bus DMA mask as appropriate To: Christoph Hellwig Cc: devicetree@vger.kernel.org, gregkh@linuxfoundation.org, x86@kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, iommu@lists.linux-foundation.org, robh+dt@kernel.org, sudeep.holla@arm.com, frowand.list@gmail.com, linux-arm-kernel@lists.infradead.org References: <20180710180458.GC26285@lst.de> From: Robin Murphy Message-ID: Date: Wed, 11 Jul 2018 19:03:55 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180710180458.GC26285@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/07/18 19:04, Christoph Hellwig wrote: > On Tue, Jul 10, 2018 at 06:17:17PM +0100, Robin Murphy wrote: >> When an explicit DMA limit is described by firmware, we need to remember >> it regardless of how drivers might subsequently update their devices' >> masks. The new bus_dma_mask field does that. > > Shouldn't we also stop presetting the dma mask after this? I guess initialising the device masks here only really has any effect if drivers fail to set their own, so if we're getting stricter about that then it would make sense to stop; I'll add a couple of patches on top to clean that up. Robin.