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=-8.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 E2E4EC433E2 for ; Thu, 17 Sep 2020 11:47:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A8BA5206C9 for ; Thu, 17 Sep 2020 11:47:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="QitX2hEb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726873AbgIQLrb (ORCPT ); Thu, 17 Sep 2020 07:47:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726185AbgIQLrV (ORCPT ); Thu, 17 Sep 2020 07:47:21 -0400 Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C57B8C06174A; Thu, 17 Sep 2020 04:47:20 -0700 (PDT) Received: by mail-wr1-x443.google.com with SMTP id x14so1699031wrl.12; Thu, 17 Sep 2020 04:47:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=CsSULRHEwOUPa0oBdSSa2xFRccNBYxIxudhxZxhguzQ=; b=QitX2hEbnZeGW/PJejcn2xiUVk97n/t1hg3QgOSFJXVTo1UxxAiXTS6yyXT8XipbTs nqdZMmAtQVBpv0q8+8DRERuHhMfvo+8fCS0w31oIY9vXSPj8mhats3h48EFUliUNdYij M0mIW21JLzG+nQ91I0ym9jPK6QAwVfO7rn5vjOVVLsEe/qRcnOStBU+C5DTBPo3BHqAH U5FLdmKmmD4aLX0OPWKo6x1hBNYQ1e9JAYG/Y9c8pqZJgr55D2EBPseMPHSnV1E0eopC CSdpzdLqtfTPJ1+IhmVnOURgEilywrGFF4N7PS9PeiKXl2NexFTKQU7K2I+Lzin8mWk4 t9Gg== 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:in-reply-to:user-agent; bh=CsSULRHEwOUPa0oBdSSa2xFRccNBYxIxudhxZxhguzQ=; b=gPuDNhDIC92YEUN1u3BtHzYqhPGZmKVrbmwFVJbVetzXerp94XPC3X/r8r+QIUTlAP thQSjmruQQqpZn3SHPrM2ZHqQoN4RA35nfJrTjNsZt+LTM7uJSGSMLJBCsC83Tsy212p KN5ASDuGQLYcGvYiHTnjNb4YoMCwpk5jihZL5IHIw7JsByzaGF4FdZ43H06KE3nLh6BN dqCiweiHI6RtuCxx8OF0CBz/KlnT2fY7RTRHvKXTiDS/NKvu1LbZ9TqS4iCVaJ1GzCUW DM1EHtHYRylbpO7TlucrPVhcJxE7T0kQzLmfNqks+WaBzwXe253YqAx/0Sxf/bTPU/ia wQng== X-Gm-Message-State: AOAM532uakGNlotmLv2qtF/b1iEenHBVaDaPYjafQVDZIq8geyS+f1zy eVAkAmKUbk1RE5fwdBE/L3s= X-Google-Smtp-Source: ABdhPJz+yKz3QpNLXp/JzXcrh9g10SAeQ/RabQPP8fMs6W/gl/lwTvxyNClHAnNctIYQvKWAa9vquQ== X-Received: by 2002:a5d:458a:: with SMTP id p10mr30826324wrq.282.1600343239531; Thu, 17 Sep 2020 04:47:19 -0700 (PDT) Received: from localhost ([217.111.27.204]) by smtp.gmail.com with ESMTPSA id q15sm36499027wrr.8.2020.09.17.04.47.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Sep 2020 04:47:18 -0700 (PDT) Date: Thu, 17 Sep 2020 13:47:16 +0200 From: Thierry Reding To: Dmitry Osipenko Cc: Jonathan Hunter , Laxman Dewangan , Wolfram Sang , =?utf-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= , Andy Shevchenko , linux-i2c@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 21/34] i2c: tegra: Don't fall back to PIO mode if DMA configuration fails Message-ID: <20200917114716.GZ3515672@ulmo> References: <20200908224006.25636-1-digetx@gmail.com> <20200908224006.25636-22-digetx@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Wn0J+vu9+NMIXK57" Content-Disposition: inline In-Reply-To: <20200908224006.25636-22-digetx@gmail.com> User-Agent: Mutt/1.14.6 (2020-07-11) Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org --Wn0J+vu9+NMIXK57 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Sep 09, 2020 at 01:39:53AM +0300, Dmitry Osipenko wrote: > The DMA code path has been tested well enough and the DMA configuration > performed by tegra_i2c_config_fifo_trig() shouldn't ever fail in practice. > Hence let's remove the obscure transfer-mode switching in order to have a > cleaner and simpler code. Now I2C transfer will be failed if DMA > configuration fails. >=20 > Signed-off-by: Dmitry Osipenko > --- > drivers/i2c/busses/i2c-tegra.c | 18 ++++++++++-------- > 1 file changed, 10 insertions(+), 8 deletions(-) I'm not sure that's a good idea. It's always possible that the DMA setup is going to break because of something that's not related to the I2C driver itself. Having the system completely break instead of falling back to PIO mode seems like it would only complicate troubleshooting any such issues. 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