From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sricharan R Subject: Re: [V9, 07/11] iommu: of: Handle IOMMU lookup failure with deferred probing or error Date: Tue, 28 Mar 2017 21:36:30 +0530 Message-ID: <7312ddb8-3d6e-0665-9e7e-1a39c6fb597b@codeaurora.org> References: <1489086061-9356-8-git-send-email-sricharan@codeaurora.org> <20170328150001.j57jko6mx35npgp2@rob-hp-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]:35060 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751386AbdC1QGq (ORCPT ); Tue, 28 Mar 2017 12:06:46 -0400 In-Reply-To: <20170328150001.j57jko6mx35npgp2@rob-hp-laptop> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Rob Herring Cc: lorenzo.pieralisi@arm.com, linux-arm-msm@vger.kernel.org, joro@8bytes.org, will.deacon@arm.com, robdclark@gmail.com, okaya@codeaurora.org, linux-acpi@vger.kernel.org, iommu@lists.linux-foundation.org, hanjun.guo@linaro.org, linux-pci@vger.kernel.org, bhelgaas@google.com, tn@semihalf.com, robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org, m.szyprowski@samsung.com Hi, On 3/28/2017 8:30 PM, Rob Herring wrote: > On Fri, Mar 10, 2017 at 12:30:57AM +0530, Sricharan R wrote: >> From: Laurent Pinchart >> >> Failures to look up an IOMMU when parsing the DT iommus property need to >> be handled separately from the .of_xlate() failures to support deferred >> probing. >> >> The lack of a registered IOMMU can be caused by the lack of a driver for >> the IOMMU, the IOMMU device probe not having been performed yet, having >> been deferred, or having failed. >> >> The first case occurs when the device tree describes the bus master and >> IOMMU topology correctly but no device driver exists for the IOMMU yet >> or the device driver has not been compiled in. Return NULL, the caller >> will configure the device without an IOMMU. >> >> The second and third cases are handled by deferring the probe of the bus >> master device which will eventually get reprobed after the IOMMU. >> >> The last case is currently handled by deferring the probe of the bus >> master device as well. A mechanism to either configure the bus master >> device without an IOMMU or to fail the bus master device probe depending >> on whether the IOMMU is optional or mandatory would be a good >> enhancement. >> >> Tested-by: Marek Szyprowski >> Signed-off-by: Laurent Pichart >> Signed-off-by: Sricharan R >> --- >> drivers/base/dma-mapping.c | 5 +++-- >> drivers/iommu/of_iommu.c | 4 ++-- >> drivers/of/device.c | 7 ++++++- >> include/linux/of_device.h | 9 ++++++--- >> 4 files changed, 17 insertions(+), 8 deletions(-) > > Maybe it is the same issue reported for VFIO, but virtio-pci is broken > with v8 of this series. Bisecting blames this commit which looks like it > hasn't changeed. Ya, as Robin mentioned it was broken at patch #2 and comes out after this patch. I am going to repost this series with couple of more fixes added as well. > > Rob > > P.S. Doesn't look like you have copied the DT maintainers nor list for > the DT changes. Ha, really sorry about that. will add it. Regards, Sricharan -- "QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation