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 5AA9EC433EF for ; Mon, 21 Mar 2022 20:06:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352898AbiCUUIP (ORCPT ); Mon, 21 Mar 2022 16:08:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39334 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232223AbiCUUIN (ORCPT ); Mon, 21 Mar 2022 16:08:13 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6E53749CAE; Mon, 21 Mar 2022 13:06:47 -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 08A961042; Mon, 21 Mar 2022 13:06:47 -0700 (PDT) Received: from [10.57.43.230] (unknown [10.57.43.230]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 391603F66F; Mon, 21 Mar 2022 13:06:45 -0700 (PDT) Message-ID: Date: Mon, 21 Mar 2022 20:06:40 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH v2 0/2] PCI: xgene: Restore working PCIe functionnality Content-Language: en-GB To: Marc Zyngier , Rob Herring Cc: "linux-kernel@vger.kernel.org" , linux-arm-kernel , PCI , Toan Le , Lorenzo Pieralisi , =?UTF-8?Q?Krzysztof_Wilczy=c5=84ski?= , Bjorn Helgaas , =?UTF-8?Q?St=c3=a9phane_Graber?= , dann frazier , Android Kernel Team References: <20220321104843.949645-1-maz@kernel.org> <87h77rxnyl.wl-maz@kernel.org> <87fsnbxgau.wl-maz@kernel.org> From: Robin Murphy In-Reply-To: <87fsnbxgau.wl-maz@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022-03-21 19:21, Marc Zyngier wrote: > On Mon, 21 Mar 2022 18:03:27 +0000, > Rob Herring wrote: >> >> On Mon, Mar 21, 2022 at 11:36 AM Marc Zyngier wrote: >>> >>> On Mon, 21 Mar 2022 15:17:34 +0000, >>> Rob Herring wrote: >>>> >>>> On Mon, Mar 21, 2022 at 5:49 AM Marc Zyngier wrote: >>>>> >>>> For XGene-1, I'd still like to understand what the issue is. Reverting >>>> the first fix and fixing 'dma-ranges' should have fixed it. I need a >>>> dump of how the IB registers are initialized in both cases. I'm not >>>> saying changing 'dma-ranges' in the firmware is going to be required >>>> here. There's a couple of other ways we could fix that without a >>>> firmware change, but first I need to understand why it broke. >>> >>> Reverting 6dce5aa59e0b was enough for me, without changing anything >>> else. >> >> Meaning c7a75d07827a didn't matter for you. I'm not sure that it would. >> >> Can you tell me what 'dma-ranges' contains on your system? > > Each pcie node (all 5 of them) has: > > dma-ranges = <0x42000000 0x80 0x00 0x80 0x00 0x00 0x80000000 > 0x42000000 0x00 0x00 0x00 0x00 0x80 0x00>; Hmm, is there anyone other than iommu-dma who actually depends on the resource list being sorted in ascending order of bus address? I recall at the time I pushed for creating the list in sorted order as it was the simplest and most efficient option, but there's no technical reason we couldn't create it in as-found order and defer the sorting until iova_reserve_pci_windows() (at worst that could even operate on a temporary copy if need be). It's just more code, which didn't need to exist without a good reason, but if this is one then exist it certainly may. Cheers, Robin.