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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 D7762C282CE for ; Mon, 8 Apr 2019 09:54:11 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5E73F20870 for ; Mon, 8 Apr 2019 09:54:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5E73F20870 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 44d5Nc5MzkzDqFH for ; Mon, 8 Apr 2019 19:54:08 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=huawei.com (client-ip=45.249.212.191; helo=huawei.com; envelope-from=thunder.leizhen@huawei.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com Received: from huawei.com (szxga05-in.huawei.com [45.249.212.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 44d5Lq5dKRzDqFH for ; Mon, 8 Apr 2019 19:52:35 +1000 (AEST) Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 633868A0D550D054A9A4; Mon, 8 Apr 2019 17:52:06 +0800 (CST) Received: from [127.0.0.1] (10.177.23.164) by DGGEMS405-HUB.china.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.408.0; Mon, 8 Apr 2019 17:51:59 +0800 Subject: Re: [PATCH v4 0/6] normalize IOMMU dma mode boot options To: Thomas Gleixner References: <20190407124147.13576-1-thunder.leizhen@huawei.com> <5CAABD03.9000301@huawei.com> From: "Leizhen (ThunderTown)" Message-ID: <5CAB19BC.2040804@huawei.com> Date: Mon, 8 Apr 2019 17:51:56 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.23.164] X-CFilter-Loop: Reflected X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-ia64 , Sebastian Ott , linux-doc , Hanjun Guo , Heiko Carstens , Paul Mackerras , "H . Peter Anvin" , linux-s390 , Jonathan Corbet , Jean-Philippe Brucker , Joerg Roedel , x86 , Ingo Molnar , Fenghua Yu , Will Deacon , John Garry , linuxppc-dev , Borislav Petkov , Gerald Schaefer , Tony Luck , David Woodhouse , linux-kernel , iommu , Martin Schwidefsky , Robin Murphy Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 2019/4/8 14:32, Thomas Gleixner wrote: > On Mon, 8 Apr 2019, Leizhen (ThunderTown) wrote: >>> >>> This will break systems using boot options as now, and I think >>> this is unacceptable. If you want to do so, just introduce iommu.dma_mode >>> on top of those iommu boot options with dma mode boot options unchanged, >>> and iommu.dma_mode is for all archs but compatible with them. >> >> I just changed the boot options name, but keep the function no change. I added >> all related maintainers/supporters in the "to=" list, maybe we can disuss this. > > Changing the name _IS_ the problem. Think about unattended updates. > >> Should I add some "obsoleted" warnings for old options and keep them for a while? > > No, just keep the old options around for backwards compatibilty sake. We > just do not add new arch specific options in the future. New options need > to use the generic iommu.dma_mode name space. OK, thanks for your advise. > > Thanks, > > tglx > > . > -- Thanks! BestRegards