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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 791C4C6FD1C for ; Wed, 22 Mar 2023 09:02:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229987AbjCVJCt (ORCPT ); Wed, 22 Mar 2023 05:02:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47652 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229635AbjCVJCr (ORCPT ); Wed, 22 Mar 2023 05:02:47 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id ADA525B5C0 for ; Wed, 22 Mar 2023 02:02:46 -0700 (PDT) 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 35B324B3; Wed, 22 Mar 2023 02:03:30 -0700 (PDT) Received: from [10.57.53.137] (unknown [10.57.53.137]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 40A923F6C4; Wed, 22 Mar 2023 02:02:44 -0700 (PDT) Message-ID: <85607806-b888-2d5e-67a4-e9d63ebd1976@arm.com> Date: Wed, 22 Mar 2023 09:02:41 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [PATCH] iommu/rockchip: Add missing set_platform_dma_ops callback To: Jason Gunthorpe Cc: Heiko Stuebner , Joerg Roedel , Will Deacon , Robin Murphy , iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, Lu Baolu References: <20230315164152.333251-1-steven.price@arm.com> Content-Language: en-GB From: Steven Price In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21/03/2023 14:38, Jason Gunthorpe wrote: > On Wed, Mar 15, 2023 at 04:41:52PM +0000, Steven Price wrote: >> Similar to exynos, we need a set_platform_dma_ops() callback for proper >> operation on ARM 32 bit after recent changes in the IOMMU framework >> (detach ops removal). >> >> Fixes: c1fe9119ee70 ("iommu: Add set_platform_dma_ops callbacks") >> Signed-off-by: Steven Price >> --- >> This fixes a splat I was seeing on a Firefly-RK3288, more details here: >> https://lore.kernel.org/all/26a5d1b8-40b3-b1e4-bc85-740409c26838@arm.com/ > > Reviewed-by: Jason Gunthorpe Thanks for the review. > Do you know what state the iommu is left in after > rk_iommu_detach_device()? Ie is it blocking DMA or doing identity or > something else? To be honest I really don't know for sure. But from my small understanding of the code: rk_iommu_detach_device() ends up in rk_iommu_disable_paging() which appears to switch to identity mode ("Disable memory translation"). But I don't actually have any familiarity with the hardware block, so I might be missing something. Steve