From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S940693AbdEZOOO (ORCPT ); Fri, 26 May 2017 10:14:14 -0400 Received: from galahad.ideasonboard.com ([185.26.127.97]:36530 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751170AbdEZOOJ (ORCPT ); Fri, 26 May 2017 10:14:09 -0400 From: Laurent Pinchart To: Sricharan R Cc: robin.murphy@arm.com, will.deacon@arm.com, joro@8bytes.org, lorenzo.pieralisi@arm.com, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, m.szyprowski@samsung.com, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, linux-arch@vger.kernel.org, linux@armlinux.org.uk Subject: Re: [PATCH v2] arm: dma-mapping: Reset the device's dma_ops Date: Fri, 26 May 2017 17:14:28 +0300 Message-ID: <2754945.XA69I2mJdj@avalon> User-Agent: KMail/4.14.10 (Linux/4.9.16-gentoo; KDE/4.14.32; x86_64; ; ) In-Reply-To: <1495795417-15177-1-git-send-email-sricharan@codeaurora.org> References: <1495795417-15177-1-git-send-email-sricharan@codeaurora.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Sricharan, Thank you for the patch. On Friday 26 May 2017 16:13:37 Sricharan R wrote: > arch_teardown_dma_ops() being the inverse of arch_setup_dma_ops() > ,dma_ops should be cleared in the teardown path. Currently, only the > device's iommu mapping structures are cleared in arch_teardown_dma_ops, > but not the dma_ops. So on the next reprobe, dma_ops left in place is > stale from the first IOMMU setup, but iommu mappings has been disposed > of. This is a problem when the probe of the device is deferred and > recalled with the IOMMU probe deferral. > > So for fixing this, slightly refactor by moving the code from > __arm_iommu_detach_device to arm_iommu_detach_device and cleanup > the former. This takes care of resetting the dma_ops in the teardown > path. > > Signed-off-by: Sricharan R > Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for > platform/amba/pci bus devices") Reviewed-by: Laurent Pinchart Could you please push this upstream along with "[PATCH] ARM: dma-mapping: Don't tear third-party mappings" ? (And feel free to s/tear/tear down/ in the subject of that patch, I've only noticed now that I forgot one word) > --- > arch/arm/mm/dma-mapping.c | 25 ++++++++++--------------- > 1 file changed, 10 insertions(+), 15 deletions(-) > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > index c742dfd..6e82e87 100644 > --- a/arch/arm/mm/dma-mapping.c > +++ b/arch/arm/mm/dma-mapping.c > @@ -2311,7 +2311,14 @@ int arm_iommu_attach_device(struct device *dev, > } > EXPORT_SYMBOL_GPL(arm_iommu_attach_device); > > -static void __arm_iommu_detach_device(struct device *dev) > +/** > + * arm_iommu_detach_device > + * @dev: valid struct device pointer > + * > + * Detaches the provided device from a previously attached map. > + * This voids the dma operations (dma_map_ops pointer) > + */ > +void arm_iommu_detach_device(struct device *dev) > { > struct dma_iommu_mapping *mapping; > > @@ -2324,22 +2331,10 @@ static void __arm_iommu_detach_device(struct device > *dev) iommu_detach_device(mapping->domain, dev); > kref_put(&mapping->kref, release_iommu_mapping); > to_dma_iommu_mapping(dev) = NULL; > + set_dma_ops(dev, NULL); > > pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev)); > } > - > -/** > - * arm_iommu_detach_device > - * @dev: valid struct device pointer > - * > - * Detaches the provided device from a previously attached map. > - * This voids the dma operations (dma_map_ops pointer) > - */ > -void arm_iommu_detach_device(struct device *dev) > -{ > - __arm_iommu_detach_device(dev); > - set_dma_ops(dev, NULL); > -} > EXPORT_SYMBOL_GPL(arm_iommu_detach_device); > > static const struct dma_map_ops *arm_get_iommu_dma_map_ops(bool coherent) > @@ -2379,7 +2374,7 @@ static void arm_teardown_iommu_dma_ops(struct device > *dev) if (!mapping) > return; > > - __arm_iommu_detach_device(dev); > + arm_iommu_detach_device(dev); > arm_iommu_release_mapping(mapping); > } -- Regards, Laurent Pinchart