Received: by 2002:a25:f815:0:0:0:0:0 with SMTP id u21csp2930471ybd; Thu, 27 Jun 2019 23:23:05 -0700 (PDT) X-Google-Smtp-Source: APXvYqxR4elsUGBWYWh4mowh9BO2k5tMaaxH6vTKQR1WizvxsIfKVBanlqQbEfJNhT8E8J+0lPv6 X-Received: by 2002:a63:7a01:: with SMTP id v1mr4073516pgc.310.1561702985348; Thu, 27 Jun 2019 23:23:05 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1561702985; cv=none; d=google.com; s=arc-20160816; b=ZkHK5CfKb1VdzeOtaoE9if375h6TLOOoVxLsr7LaNCjl92eeOuI8UeWQX1bUtlsxyy Sqw0VnPEeO+naPrg9ROcYNdjN4WpJJtGD0FOI3SFUwtBMDFXbTbP3YJY4AsoJgds63h/ LMftVQRZbcDAWwR8j5CLCMCxwQY46HulmeNDHnXnhze5n1GCTlqwYreDE3W3fO9/hjEr rdJ9T0bFlcw30aZlCIkBbuz5mKP4Z/Jd2byf5goMAwsxwgDTPQvLuzSWLbKuviUNfTOw SjxjIzuvNK0dONlYo987evU5IpUMeuGrU8xfXQAzLyfvBOduvzWapiUr0t/4u+HGn/MG aM6Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:in-reply-to:mime-version:user-agent:date :message-id:from:references:cc:to:subject; bh=PucmN2e3t3cgfhIy4uL3W9Hr7WXM68hzROTOUy7B8JA=; b=hEgnO5UdvUYKiYXb/IjmburvoXefQBghbZlaePe7ToPdyrdbcJqwQO26hFMBG0G3P/ hC5yCSLnGdlO8Sqe0tkckkYejIs3DGpGotpnDw434ddI8KKQb5saCqjkAho5kJtowMJs 0RDGkjst3sEnBIZDPAxSbMzT+ZIhkn1sYNr1xle3/8wgFBV+k+txsj2dzu21SrlRNm1c 4imrRLTvZb2xQzxr0YSoQCtUcJo+JeJJZErWQ1GJxvYzdI6bm+htWITR4wG78KG01iQT dYsqDWXARHzn1jmq95jvF5p1ZaMv4/rkgGX3xJMhrGH5KFP6kH0g4sQReeDxCBtdgqQj J+9w== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id d5si1273517pla.17.2019.06.27.23.22.49; Thu, 27 Jun 2019 23:23:05 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727028AbfF1GWe (ORCPT + 99 others); Fri, 28 Jun 2019 02:22:34 -0400 Received: from mga17.intel.com ([192.55.52.151]:56411 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726553AbfF1GWe (ORCPT ); Fri, 28 Jun 2019 02:22:34 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Jun 2019 23:22:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,426,1557212400"; d="scan'208";a="164573684" Received: from mylly.fi.intel.com (HELO [10.237.72.56]) ([10.237.72.56]) by fmsmga007.fm.intel.com with ESMTP; 27 Jun 2019 23:22:32 -0700 Subject: Re: [PATCH v2 08/27] i2c: busses: remove memset after dmam_alloc_coherent To: Fuqian Huang Cc: Seth Heasley , Neil Horman , Wolfram Sang , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190628024711.15203-1-huangfq.daxian@gmail.com> From: Jarkko Nikula Message-ID: Date: Fri, 28 Jun 2019 09:22:31 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190628024711.15203-1-huangfq.daxian@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi On 6/28/19 5:47 AM, Fuqian Huang wrote: > In commit af7ddd8a627c > ("Merge tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mapping"), > dmam_alloc_coherent has already zeroed the memory. > So memset is not needed. > > Signed-off-by: Fuqian Huang > --- > drivers/i2c/busses/i2c-ismt.c | 2 -- > 1 file changed, 2 deletions(-) > It would be better to refer actual commit or commits that implement that zeroing rather than merge point in commit log if possible. At quick look commit 518a2f1925c3 ("dma-mapping: zero memory returned from dma_alloc_*") is the one but I'm not really an expert here to say is that alone enough. -- Jarkko