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=-3.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 B7F1FC07E85 for ; Sun, 9 Dec 2018 04:57:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 445492081F for ; Sun, 9 Dec 2018 04:57:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 445492081F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=davemloft.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mips-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726078AbeLIE5f (ORCPT ); Sat, 8 Dec 2018 23:57:35 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:36078 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726061AbeLIE5f (ORCPT ); Sat, 8 Dec 2018 23:57:35 -0500 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::bf5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 3F18C141E13FF; Sat, 8 Dec 2018 20:57:34 -0800 (PST) Date: Sat, 08 Dec 2018 20:57:33 -0800 (PST) Message-Id: <20181208.205733.639997534873546175.davem@davemloft.net> To: hch@lst.de Cc: iommu@lists.linux-foundation.org, robin.murphy@arm.com, vgupta@synopsys.com, matwey@sai.msu.ru, laurent.pinchart@ideasonboard.com, linux-snps-arc@lists.infradead.org, ezequiel@collabora.com, linux-media@vger.kernel.org, linux-arm-kernel@lists.infradead.org, dri-devel@lists.freedesktop.org, sparclinux@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linux-mips@vger.kernel.org Subject: Re: [PATCH 1/6] sparc: remove no needed sbus_dma_ops methods From: David Miller In-Reply-To: <20181208174115.16237-2-hch@lst.de> References: <20181208174115.16237-1-hch@lst.de> <20181208174115.16237-2-hch@lst.de> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Sat, 08 Dec 2018 20:57:34 -0800 (PST) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org From: Christoph Hellwig Date: Sat, 8 Dec 2018 09:41:10 -0800 > No need to BUG_ON() on the cache maintainance ops - they are no-ops > by default, and there is nothing in the DMA API contract that prohibits > calling them on sbus devices (even if such drivers are unlikely to > ever appear). > > Similarly a dma_supported method that always returns 0 is rather > pointless. The only thing that indicates is that no one ever calls > the method on sbus devices. > > Signed-off-by: Christoph Hellwig Acked-by: David S. Miller