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 09770C282D8 for ; Fri, 1 Feb 2019 19:22:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CAF42218F0 for ; Fri, 1 Feb 2019 19:22:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="tXI5lyxz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731383AbfBATWa (ORCPT ); Fri, 1 Feb 2019 14:22:30 -0500 Received: from mail-lf1-f68.google.com ([209.85.167.68]:46234 "EHLO mail-lf1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726721AbfBATW3 (ORCPT ); Fri, 1 Feb 2019 14:22:29 -0500 Received: by mail-lf1-f68.google.com with SMTP id f5so5854352lfc.13; Fri, 01 Feb 2019 11:22:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=jcHEnwfAZuHLTMg4V9t3DKGfozIaFiYprA0Dz/mQ3oY=; b=tXI5lyxzJhyx7b8n8GSPDfrAMap9b+609i1xnFOX1442aGjFHEBFJhPAjey2o4k4lu H3qRC5CoRLLxFxQwUEa68emcb6Zh6ZbMq5Xe7cIuiSLo+DbXjPBdBr8A0f+ruoOCa5sf wWWqazznIVFilJey+nmVUP3PuYYLvAEu7B2xJ8BAlkdFuVcOAF3nt/5g1B7EJXq9orCE cgiIVTAxCd2cCzXAufxXmVXfVBwewok0yJAxqLmW2aboA3zXUufBlug60yVrKcIq0zXr Xqpmxt81b5aDjN3YFMB/mYs9SFWtI3/FvEvDAk0rmyxiZXoB/Ya9eBRiTU7gVDfbqFl9 +LYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=jcHEnwfAZuHLTMg4V9t3DKGfozIaFiYprA0Dz/mQ3oY=; b=jzna0yy+LY7pUs8iOoCm3iQSzpNbMoLWIK6gFXEyDSbxQgjtkvb37dGPK8ufKYtvso QtxtTtG9hVFIAzcnGnBOCLVQfov2APtEfM1nB1nK5akCSxydhkAFcbbGBJqRDXXSZXX2 6zz4bL9OhCfVFA1E4+z2qP8TlFHVjSxa0WVICyX3zDhwBJdzES0R1h+GO48FxYQ6bGoJ f6JJeV41lUTcAV1SOSq5SBpT+o8/+iSSgIOrkTLIjNkukUTN2981VFWtwoiJvLnJmP/O UV2267m/KbQYcjvMj9srjGEQ051dxKcLdlweeBFAs9e36hFVZ2ECrmZ//tRrOvnJOer1 ZFHg== X-Gm-Message-State: AJcUukfATBTGkubJpzvdeyB6YaZHmUeoPzt4ZbUQwn6KxQOm6DfM1HMq dAXBVCfgG5qn/h/6Y945ZkEaNW2D X-Google-Smtp-Source: ALg8bN7fCRj9UgP51fwCc19DBm+gLLLINhDrTSHNkiwPJZdRWwN5e6yziSbD7uaoYiWNMEcA65gGFw== X-Received: by 2002:a19:cd50:: with SMTP id d77mr31654887lfg.125.1549048947153; Fri, 01 Feb 2019 11:22:27 -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 t23sm1512654lfl.59.2019.02.01.11.22.25 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 01 Feb 2019 11:22:26 -0800 (PST) Subject: Re: [PATCH V9 3/5] i2c: tegra: Add DMA support To: Sowjanya Komatineni , "thierry.reding@gmail.com" , Jonathan Hunter , Mantravadi Karthik , Shardar Mohammed , Timo Alho Cc: "linux-tegra@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-i2c@vger.kernel.org" References: <1549040867-18149-1-git-send-email-skomatineni@nvidia.com> <1549040867-18149-3-git-send-email-skomatineni@nvidia.com> <951cf1f5-ba3a-94ef-0399-2259effebc99@gmail.com> From: Dmitry Osipenko Message-ID: <6150de70-6ca8-944a-780a-4574ff2b21c7@gmail.com> Date: Fri, 1 Feb 2019 22:22:25 +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 01.02.2019 22:20, Sowjanya Komatineni пишет: > >>> +static int tegra_i2c_init_dma(struct tegra_i2c_dev *i2c_dev) { >>> + struct dma_chan *dma_chan; >>> + u32 *dma_buf; >>> + dma_addr_t dma_phys; >>> + int err = 0; >>> + >>> + if (!IS_ENABLED(CONFIG_TEGRA20_APB_DMA)) >>> + return -ENODEV; >> >> Driver shall not fail to probe if DMA driver is disabled, but to continue with the PIO-only mode available. >> >> Should be: >> >> if (!IS_ENABLED(CONFIG_TEGRA20_APB_DMA)) >> return 0; >> > Except EPROBE_DEFER, anything else returned from tegra_i2c_init_dma (ENODEV/ENOMEM) is ignored in i2c_probe > DMA mode decision is based on xfer size and availability of dma channel or can be changed based on valid dma buf to shorten the line. > Ah, sorry. I missed that, seems good then.