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=-9.6 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY, 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 E16E4C433DF for ; Thu, 20 Aug 2020 23:01:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C23EF2075E for ; Thu, 20 Aug 2020 23:01:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728625AbgHTXBr (ORCPT ); Thu, 20 Aug 2020 19:01:47 -0400 Received: from foss.arm.com ([217.140.110.172]:46972 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728368AbgHTXBq (ORCPT ); Thu, 20 Aug 2020 19:01:46 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C6C6331B; Thu, 20 Aug 2020 16:01:44 -0700 (PDT) Received: from [10.57.40.122] (unknown [10.57.40.122]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 98AAB3F71F; Thu, 20 Aug 2020 16:01:39 -0700 (PDT) Subject: Re: [PATCH 17/18] media/omap3isp: Clean up IOMMU workaround To: Sakari Ailus Cc: hch@lst.de, joro@8bytes.org, linux@armlinux.org.uk, will@kernel.org, inki.dae@samsung.com, sw0312.kim@samsung.com, kyungmin.park@samsung.com, m.szyprowski@samsung.com, agross@kernel.org, bjorn.andersson@linaro.org, thierry.reding@gmail.com, jonathanh@nvidia.com, vdumpa@nvidia.com, digetx@gmail.com, matthias.bgg@gmail.com, yong.wu@mediatek.com, geert+renesas@glider.be, magnus.damm@gmail.com, t-kristo@ti.com, s-anna@ti.com, laurent.pinchart@ideasonboard.com, linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, linux-samsung-soc@vger.kernel.org, linux-tegra@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mediatek@lists.infradead.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org References: <11d8419744e4e744a9448180801b0c4683328afd.1597931876.git.robin.murphy@arm.com> <20200820165339.GK7145@valkosipuli.retiisi.org.uk> <20200820195536.GL7145@valkosipuli.retiisi.org.uk> From: Robin Murphy Message-ID: <5190a40e-ad24-d98e-3588-b95592ea2db3@arm.com> Date: Fri, 21 Aug 2020 00:01:38 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200820195536.GL7145@valkosipuli.retiisi.org.uk> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-08-20 20:55, Sakari Ailus wrote: > On Thu, Aug 20, 2020 at 06:25:19PM +0100, Robin Murphy wrote: >> On 2020-08-20 17:53, Sakari Ailus wrote: >>> Hi Robin, >>> >>> On Thu, Aug 20, 2020 at 04:08:36PM +0100, Robin Murphy wrote: >>>> Now that arch/arm is wired up for default domains and iommu-dma, devices >>>> behind IOMMUs will get mappings set up automatically as appropriate, so >>>> there is no need for drivers to do so manually. >>>> >>>> Signed-off-by: Robin Murphy >>> >>> Thanks for the patch. >> >> Many thanks for testing so quickly! >> >>> I haven't looked at the details but it seems that this causes the buffer >>> memory allocation to be physically contiguous, which causes a failure to >>> allocate video buffers of entirely normal size. I guess that was not >>> intentional? >> >> Hmm, it looks like the device ends up with the wrong DMA ops, which implies >> something didn't go as expected with the earlier IOMMU setup and default >> domain creation. Chances are that either I missed some subtlety in the >> omap_iommu change, or I've fundamentally misjudged how the ISP probing works >> and it never actually goes down the of_iommu_configure() path in the first >> place. Do you get any messages from the IOMMU layer earlier on during boot? > > I do get these: > > [ 2.934936] iommu: Default domain type: Translated > [ 2.940917] omap-iommu 480bd400.mmu: 480bd400.mmu registered > [ 2.946899] platform 480bc000.isp: Adding to iommu group 0 > So that much looks OK, if there are no obvious errors. Unfortunately there's no easy way to tell exactly what of_iommu_configure() is doing (beyond enabling a couple of vague debug messages). The first thing I'll do tomorrow is double-check whether it's really working on my boards here, or whether I was just getting lucky with CMA... (I assume you don't have CMA enabled if you're ending up in remap_allocator_alloc()) Robin.