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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 2F431C282C2 for ; Thu, 7 Feb 2019 20:22:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EBEDC21721 for ; Thu, 7 Feb 2019 20:22:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Nbv79Jep" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727435AbfBGUW4 (ORCPT ); Thu, 7 Feb 2019 15:22:56 -0500 Received: from mail-lj1-f193.google.com ([209.85.208.193]:37175 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727124AbfBGUWz (ORCPT ); Thu, 7 Feb 2019 15:22:55 -0500 Received: by mail-lj1-f193.google.com with SMTP id r10-v6so1047091ljj.4; Thu, 07 Feb 2019 12:22:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:from:to:cc:references:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=+B67LYoqXEZgeZGgkzwc/fnxIm1aheEgyK7zgsFPlSk=; b=Nbv79JepX9P39OgKZXa82WGuwgp9S0yD/qGwigDlj1gI+IGCS6dvpog/oEJPiuOcR0 xrhoRA+SACVHU7+IO6jUdk0ordykJhjP02WLPJfjbV/gQ+aD8r9EnpTW7sumdz4Z9ue+ lxNic4jfaoBiPsLiXq/K5FUkLQV0ZxbycbITlPslICTmC+eyhGJsWXZSzOFP1lv06Swm nzlJhdlVVTdFm/ZVEkWo+rkUJj/jcerDmM82fYcQWk8FwjROJE9jDoYrqy2tZiINByeX FD6+8mRh3HbEyBwqovSua0gXNcW4MphFQbYzfx+MtmZl68h7j5fFqb5b/2uFP42PS4Yi Cyug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:references:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=+B67LYoqXEZgeZGgkzwc/fnxIm1aheEgyK7zgsFPlSk=; b=tTScjyf6Fo0AGvsGftAet96eq9pD53HWdBTcMr3d9FQxjUUOcMcAblwGDYdzx1SN7R flnGSPcsKuHUdBvig/dh07ZndtXokn4WYUsehX3zjK1G7RWkrK8LDv3dN54F/YeCC8Qf POonVFXOr9Almg4EQWzFGht5GPmMAhBUPGoXeRH8ptSx1XbzdqF7eGeyv+w56AhMYUux /hSWijoPSOEgg1qVghLgybEq5g5qWtO4aqi3iOe52WCywKBTJ34GzoV8GNHhdnoY88nU pwhvPcX4S484MawG6k/5rE80SISGkaXkqOUnuKk5airLDxPRMbWxXxZv49mlQyQQF6Bh M57Q== X-Gm-Message-State: AHQUAuZDjcqAY+4SuHSTR/qirpcI0IoyFuVepm/J3NwAdX0M2GKGzc5S 0MJf8W5OlCvqu+VvA4wra9ptAoB6 X-Google-Smtp-Source: AHgI3IaWiduf7cnU91f8jUMv54pQiiiUmU3PspRBiE9nemC7JYwiTY3G5CjnMffoLMnS4BH2+W61Yg== X-Received: by 2002:a2e:86ca:: with SMTP id n10-v6mr9875024ljj.49.1549570973211; Thu, 07 Feb 2019 12:22:53 -0800 (PST) Received: from [192.168.2.145] (ppp91-79-175-49.pppoe.mtu-net.ru. [91.79.175.49]) by smtp.googlemail.com with ESMTPSA id v9sm5052567lfg.15.2019.02.07.12.22.51 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 07 Feb 2019 12:22:52 -0800 (PST) Subject: Re: [PATCH V14 3/5] i2c: tegra: Add DMA support From: Dmitry Osipenko To: Sowjanya Komatineni , thierry.reding@gmail.com, jonathanh@nvidia.com, mkarthik@nvidia.com, smohammed@nvidia.com, talho@nvidia.com Cc: linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org References: <1549480569-24860-1-git-send-email-skomatineni@nvidia.com> <1549480569-24860-3-git-send-email-skomatineni@nvidia.com> Message-ID: Date: Thu, 7 Feb 2019 23:22:48 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 07.02.2019 22:14, Dmitry Osipenko пишет: > 06.02.2019 22:16, Sowjanya Komatineni пишет: >> +static void tegra_i2c_config_fifo_trig(struct tegra_i2c_dev *i2c_dev, >> + size_t len) >> +{ >> + u32 val = 0, reg; >> + u8 dma_burst = 0; There is no need to set dma_burst to zero as well. In general you only need to initialize variables if code uses the uninitialized variable. >> + struct dma_slave_config slv_config = {0}; >> + struct dma_chan *chan; >> + int ret; >> + unsigned long reg_offset; >> + >> + if (i2c_dev->hw->has_mst_fifo) >> + reg = I2C_MST_FIFO_CONTROL; >> + else >> + reg = I2C_FIFO_CONTROL; >> + >> + if (i2c_dev->is_curr_dma_xfer) { >> + if (len & 0xF) >> + dma_burst = 1; >> + else if (len & 0x10) >> + dma_burst = 4; >> + else >> + dma_burst = 8; In this case compiler just ignores the first initialization because it is explicitly initialized later on in the code path that actually uses the dma_burst variable. Avoiding unnecessary initialization helps to keep code a bit more clean.