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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 915B1C11F68 for ; Fri, 2 Jul 2021 04:56:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6FF9661416 for ; Fri, 2 Jul 2021 04:56:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232471AbhGBE7M (ORCPT ); Fri, 2 Jul 2021 00:59:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55438 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232852AbhGBE7K (ORCPT ); Fri, 2 Jul 2021 00:59:10 -0400 Received: from mail-pg1-x529.google.com (mail-pg1-x529.google.com [IPv6:2607:f8b0:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2293C061762 for ; Thu, 1 Jul 2021 21:56:36 -0700 (PDT) Received: by mail-pg1-x529.google.com with SMTP id a2so8457419pgi.6 for ; Thu, 01 Jul 2021 21:56:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=qqSo2EHKnteCkmvIob7W7h8j2bBButMHNumXS1B2l4o=; b=THUTh9lL4gLgfoWs25q+r7nEzcReUOTkjZ6PBQSvLYhT5h22qQghqFKTbnb+SueClW yzFZUuYKHvmbk60MxqoXkPEIZT7QKSU230n1xDMIOEwPaorDYxvR+1FO6c9gXmnUAEyd jRmw9Ho2/f6zYuDYpi6/dqnwUEhzU5C9ovYEp1pvzM/GkwAC5SJQdnZMiT9DQsTp3we/ sIht4/YeX7Sq2U/klwO/Men0mMiCPsDJsV+ip84CFwlRVcNtk1HMWKNMqPPCxaTt42f8 Ts26/9nOMSVMKIGqnJ4Kejd/m3y2N8FnH+a2Kij8aGj64AQIdpA7vu2IusgPFP7lMtgD GrGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=qqSo2EHKnteCkmvIob7W7h8j2bBButMHNumXS1B2l4o=; b=SlhnxzfG5rVgA1GA1q6iwAg107PyvzwVbfK45SAwW4slWRpLxCJpVq80PU8GEgpF0o P7pF7z2JovjCDVJ8eTnxomCJUUkcbiHJALfLr0JS5gu1tXuCVWYIoUaIp20e3zbcUi3Z hIcXwDg4gAzm66a9ulFVnE3YAHOSgp7kmfoUyni+k2P15kZwmPwg4qijnnsg5C/tTFs4 GKfRVm23bjrbsR9p2OXWNFxb0ttHXH3GHhkPCsEc7eWDJNV0GYmhWf2qIpXfxdhLYj5E jI5PlJLv0FWrnfpRWD7c7HVAfP2ch/he3qGO891yYpu9S5/35G+8LQqj+7u92YnMXXAQ ngGw== X-Gm-Message-State: AOAM531cJk7N7U9a7KkhK3yWXx1J+zmmnT4a4EtZLBp/uX4JIWRW05I2 NDSTyFKyUpThQEWvgl3dLbPMrg== X-Google-Smtp-Source: ABdhPJzQoHvs4UddAnwcfgRrte2ZXexLQGMoAiszR4up3WGDmvkA5xdPaNw7h+vVUySdvsIcdSrxSg== X-Received: by 2002:aa7:96cf:0:b029:30f:d1e8:9264 with SMTP id h15-20020aa796cf0000b029030fd1e89264mr3262408pfq.33.1625201796138; Thu, 01 Jul 2021 21:56:36 -0700 (PDT) Received: from localhost ([106.201.108.2]) by smtp.gmail.com with ESMTPSA id w6sm1824644pgh.56.2021.07.01.21.56.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 01 Jul 2021 21:56:35 -0700 (PDT) Date: Fri, 2 Jul 2021 10:26:33 +0530 From: Viresh Kumar To: Jie Deng Cc: linux-i2c@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, wsa@kernel.org, wsa+renesas@sang-engineering.com, mst@redhat.com, arnd@arndb.de, jasowang@redhat.com, andriy.shevchenko@linux.intel.com, yu1.wang@intel.com, shuo.a.liu@intel.com, conghui.chen@intel.com, stefanha@redhat.com Subject: Re: [PATCH v11] i2c: virtio: add a virtio i2c frontend driver Message-ID: <20210702045633.gblpud7wcffd5kyj@vireshk-i7> References: <510c876952efa693339ab0d6cc78ba7be9ef6897.1625104206.git.jie.deng@intel.com> <20210701040436.p7kega6rzeqz5tlm@vireshk-i7> <20210701061846.7u4zorimzpmb66v7@vireshk-i7> <34092cb2-03f9-231d-8769-4e45ed51c30f@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <34092cb2-03f9-231d-8769-4e45ed51c30f@intel.com> User-Agent: NeoMutt/20180716-391-311a52 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org On 02-07-21, 11:36, Jie Deng wrote: > OK. Let's add the following two lines to make sure that msg_buf is only > sent when the msgs len is not zero. And backend judges whether it is > a zero-length request by checking the number of elements received. > >  + if (msgs[i].len) { >            reqs[i].buf = i2c_get_dma_safe_msg_buf(&msgs[i], 1); >            if (!reqs[i].buf) >                    break; > >           sg_init_one(&msg_buf, reqs[i].buf, msgs[i].len); > >           if (msgs[i].flags & I2C_M_RD) >                   sgs[outcnt + incnt++] = &msg_buf; >           else >                   sgs[outcnt++] = &msg_buf; > +} Perfect. Thanks. -- viresh