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=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 E59B5C07E95 for ; Fri, 16 Jul 2021 16:18:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CDE5E61374 for ; Fri, 16 Jul 2021 16:18:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229821AbhGPQVH (ORCPT ); Fri, 16 Jul 2021 12:21:07 -0400 Received: from ale.deltatee.com ([204.191.154.188]:57206 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229692AbhGPQVF (ORCPT ); Fri, 16 Jul 2021 12:21:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:In-Reply-To:MIME-Version:Date: Message-ID:From:References:Cc:To:content-disposition; bh=BnhY0izzSFVDQcuht2cro6XvHSIBnnpJHK/4w8E4yWs=; b=lHiHBr9UmxsphzyuJXXrFvFkXJ nHnU2Aad+t4uXkXpqnoYYQXL8s0VDrTpcUrSa7MBf3lHNc8SwA72FIyA0EFnNsLaMjuY1HyVFc4eY 86UCMlrgVGkMX16Elm46rVT3dMTeEwZNCX1a+CjIpwSiCKZgO96vmX56LfZWgzS5j7bcdiascYBT7 QpZUtkyACvD3Bob5Y0jFlifJMDasY0nH1O+2FuN7wP4IsecNoMeLFw+7g7lmwXVQFM8ujekY7qsib a39261ZQjmb8njie60hE0kfk/jWrRkVOwj7hryYFQZ5ncmwJY+tyhtISQB4927wPhvb2n8G328kwr zFWziVNw==; Received: from guinness.priv.deltatee.com ([172.16.1.162]) by ale.deltatee.com with esmtp (Exim 4.92) (envelope-from ) id 1m4QXJ-0003ky-3C; Fri, 16 Jul 2021 10:18:01 -0600 To: Christoph Hellwig Cc: linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, iommu@lists.linux-foundation.org, linux-parisc@vger.kernel.org, xen-devel@lists.xenproject.org, Marek Szyprowski , Robin Murphy , Stephen Bates , Martin Oliveira References: <20210715164544.6827-1-logang@deltatee.com> <20210715164544.6827-17-logang@deltatee.com> <20210716063332.GD13345@lst.de> From: Logan Gunthorpe Message-ID: <82c0f8d8-9050-dcf7-d68d-93691878a6dd@deltatee.com> Date: Fri, 16 Jul 2021 10:17:58 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210716063332.GD13345@lst.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-CA Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 172.16.1.162 X-SA-Exim-Rcpt-To: martin.oliveira@eideticom.com, sbates@raithlin.com, robin.murphy@arm.com, m.szyprowski@samsung.com, xen-devel@lists.xenproject.org, linux-parisc@vger.kernel.org, iommu@lists.linux-foundation.org, sparclinux@vger.kernel.org, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mips@vger.kernel.org, linux-ia64@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, hch@lst.de X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: [PATCH v1 16/16] dma-mapping: Disallow .map_sg operations from returning zero on error X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On 2021-07-16 12:33 a.m., Christoph Hellwig wrote: > On Thu, Jul 15, 2021 at 10:45:44AM -0600, Logan Gunthorpe wrote: >> @@ -194,6 +194,8 @@ static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, >> else >> ents = ops->map_sg(dev, sg, nents, dir, attrs); >> >> + WARN_ON_ONCE(ents == 0); > > Turns this into a negative error code while we're at it, just to keep > the callers sane? > Sure thing. All the feedback makes sense, we'll fix it up and send a v2 in due course. Thanks, Logan