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=-13.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,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 675ABC4321A for ; Fri, 28 Jun 2019 08:59:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C4F0205ED for ; Fri, 28 Jun 2019 08:59:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="hCseVWrz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726531AbfF1I7x (ORCPT ); Fri, 28 Jun 2019 04:59:53 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:30451 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726385AbfF1I7x (ORCPT ); Fri, 28 Jun 2019 04:59:53 -0400 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 45ZrLb32q7z9v1dq; Fri, 28 Jun 2019 10:59:51 +0200 (CEST) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=hCseVWrz; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id wg0kRk6LpBEP; Fri, 28 Jun 2019 10:59:51 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 45ZrLb0JB7z9v1dW; Fri, 28 Jun 2019 10:59:51 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1561712391; bh=3PExFE1N6IiyQSDeWR2v89tJ9QeiWcAN1N4Hjay3PlI=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=hCseVWrzRRQQXlskmPHp+o3zZeA9GBRK4q98IdoDLwuXYMJZ0gqNOJzJu4lD6Mxqb cA/OiFk6yj7OXXXZDbS9ktAYJzXSFIfIfzeuxOXNEijxaOSJN+wsUKbnOH/ZnZ0Lmi Pgc6B8sCSvQ3DAwq+DJQJ9XYrlUTJvBjOpWEWRUQ= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 256308B966; Fri, 28 Jun 2019 10:59:52 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id mul6Zychpueb; Fri, 28 Jun 2019 10:59:52 +0200 (CEST) Received: from [172.25.230.101] (po15451.idsi0.si.c-s.fr [172.25.230.101]) by messagerie.si.c-s.fr (Postfix) with ESMTP id E11848B961; Fri, 28 Jun 2019 10:59:51 +0200 (CEST) Subject: Re: [PATCH v2 27/27] sound: ppc: remove unneeded memset after dma_alloc_coherent To: Fuqian Huang Cc: Rob Herring , alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Jaroslav Kysela , Richard Fontana , Paul Mackerras , Thomas Gleixner , linuxppc-dev@lists.ozlabs.org, Allison Randal References: <20190628025055.16242-1-huangfq.daxian@gmail.com> From: Christophe Leroy Followup-To: Takashi Iwai Message-ID: <83108dee-72f7-e56f-95f6-26162c9a0ccc@c-s.fr> Date: Fri, 28 Jun 2019 10:59:51 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190628025055.16242-1-huangfq.daxian@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 28/06/2019 à 04:50, Fuqian Huang a écrit : > In commit af7ddd8a627c > ("Merge tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mapping"), > dma_alloc_coherent has already zeroed the memory. > So memset is not needed. You are refering to a merge commit, is that correct ? I can't see anything related in that commit, can you please pinpoint it ? As far as I can see, on powerpc the memory has always been zeroized (since 2005 at least). Christophe > > Signed-off-by: Fuqian Huang > --- > sound/ppc/pmac.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/sound/ppc/pmac.c b/sound/ppc/pmac.c > index 1b11e53f6a62..1ab12f4f8631 100644 > --- a/sound/ppc/pmac.c > +++ b/sound/ppc/pmac.c > @@ -56,7 +56,6 @@ static int snd_pmac_dbdma_alloc(struct snd_pmac *chip, struct pmac_dbdma *rec, i > if (rec->space == NULL) > return -ENOMEM; > rec->size = size; > - memset(rec->space, 0, rsize); > rec->cmds = (void __iomem *)DBDMA_ALIGN(rec->space); > rec->addr = rec->dma_base + (unsigned long)((char *)rec->cmds - (char *)rec->space); > >