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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 343F0C07E98 for ; Mon, 5 Jul 2021 06:21:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08572613C8 for ; Mon, 5 Jul 2021 06:21:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229813AbhGEGYd (ORCPT ); Mon, 5 Jul 2021 02:24:33 -0400 Received: from mga17.intel.com ([192.55.52.151]:55416 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229797AbhGEGYd (ORCPT ); Mon, 5 Jul 2021 02:24:33 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10035"; a="189308641" X-IronPort-AV: E=Sophos;i="5.83,325,1616482800"; d="scan'208";a="189308641" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Jul 2021 23:21:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.83,325,1616482800"; d="scan'208";a="562409078" Received: from dengjie-mobl1.ccr.corp.intel.com (HELO [10.239.154.58]) ([10.239.154.58]) by fmsmga001.fm.intel.com with ESMTP; 04 Jul 2021 23:21:53 -0700 Subject: Re: [PATCH v12] i2c: virtio: add a virtio i2c frontend driver To: Viresh Kumar , Andy Shevchenko 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, yu1.wang@intel.com, shuo.a.liu@intel.com, conghui.chen@intel.com, stefanha@redhat.com References: <20210705024340.mb5sv5epxbdatgsg@vireshk-i7> From: Jie Deng Message-ID: Date: Mon, 5 Jul 2021 14:21:52 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: <20210705024340.mb5sv5epxbdatgsg@vireshk-i7> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org On 2021/7/5 10:43, Viresh Kumar wrote: > On 02-07-21, 12:58, Andy Shevchenko wrote: >> On Fri, Jul 02, 2021 at 04:46:47PM +0800, Jie Deng wrote: >>> +static int virtio_i2c_complete_reqs(struct virtqueue *vq, >>> + struct virtio_i2c_req *reqs, >>> + struct i2c_msg *msgs, int nr, >>> + bool fail) >>> +{ >>> + struct virtio_i2c_req *req; >>> + bool failed = fail; > Jie, you can actually get rid of this variable too. Jut rename fail to failed > and everything shall work as you want. Oh, You are not right. I just found we can't remove this variable. The "fail" and "failed" have different meanings for this function. We need fail to return the result. >>> + unsigned int len; >>> + int i, j = 0; >>> + >>> + for (i = 0; i < nr; i++) { >>> + /* Detach the ith request from the vq */ >>> + req = virtqueue_get_buf(vq, &len); >>> + >>> + /* >>> + * Condition (req && req == &reqs[i]) should always meet since >>> + * we have total nr requests in the vq. >>> + */ >>> + if (!failed && (WARN_ON(!(req && req == &reqs[i])) || >>> + (req->in_hdr.status != VIRTIO_I2C_MSG_OK))) >>> + failed = true; >> ...and after failed is true, we are continuing the loop, why? > Actually this function can be called with fail set to true. We proceed as we > need to call i2c_put_dma_safe_msg_buf() for all buffers we allocated earlier. > >>> + i2c_put_dma_safe_msg_buf(reqs[i].buf, &msgs[i], !failed); >>> + if (!failed) >>> + ++j; >> Besides better to read j++ the j itself can be renamed to something more >> verbose. >> >>> + } >>> + return (fail ? -ETIMEDOUT : j); >> Redundant parentheses. >> >>> +}