From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751775AbdIULD7 (ORCPT ); Thu, 21 Sep 2017 07:03:59 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:44698 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751653AbdIULD5 (ORCPT ); Thu, 21 Sep 2017 07:03:57 -0400 Subject: Re: [PATCH v2] iommu/of: Remove PCI host bridge node check To: Robin Murphy , "joro@8bytes.org" Cc: "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" References: <7ff4e56719d2e90426d9338eab00396bb2b61995.1505988973.git.robin.murphy@arm.com> <56a797382ffc65243169205c36d9f9fb1173dddd.1505989095.git.robin.murphy@arm.com> From: Jean-Philippe Brucker Message-ID: Date: Thu, 21 Sep 2017 12:08:00 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <56a797382ffc65243169205c36d9f9fb1173dddd.1505989095.git.robin.murphy@arm.com> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21/09/17 11:20, Robin Murphy wrote: > of_pci_iommu_init() tries to be clever and stop its alias walk at the > device represented by master_np, in case of weird PCI topologies where > the bridge to the IOMMU and the rest of the system is not at the root. > It turns out this is a bit short-sighted, since there are plenty of > other callers of pci_for_each_dma_alias() which would also need the same > behaviour in that situation, and the only platform so far with such a > topology (Cavium ThunderX2) already solves it more generally via a PCI > quirk. As this check is effectively redundant, and returning a boolean > value as an int is a bit broken anyway, let's just get rid of it. > > Reported-by: Jean-Philippe Brucker This fixes the 4.14-rc1 issue I had with PCI probing on the FastModel Tested-by: Jean-Philippe Brucker > Signed-off-by: Robin Murphy > --- > > Ugh, I'm really failing to spot the obvious today... > > drivers/iommu/of_iommu.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c > index e60e3dba85a0..50947ebb6d17 100644 > --- a/drivers/iommu/of_iommu.c > +++ b/drivers/iommu/of_iommu.c > @@ -157,10 +157,7 @@ static int of_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data) > > err = of_iommu_xlate(info->dev, &iommu_spec); > of_node_put(iommu_spec.np); > - if (err) > - return err; > - > - return info->np == pdev->bus->dev.of_node; > + return err; > } > > const struct iommu_ops *of_iommu_configure(struct device *dev, >