From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH] of/device: Really only set bus DMA mask when appropriate Date: Wed, 7 Nov 2018 09:03:35 +0100 Message-ID: <20181107080335.GA24511@lst.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Robin Murphy Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, aaro.koskinen-X3B1VOXEql0@public.gmane.org, jean-philippe.brucker-5wv7dgnIgG8@public.gmane.org, linux-mips-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, john.stultz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, hch-jcswGhMUV9g@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Tue, Nov 06, 2018 at 11:54:15AM +0000, Robin Murphy wrote: > of_dma_configure() was *supposed* to be following the same logic as > acpi_dma_configure() and only setting bus_dma_mask if some range was > specified by the firmware. However, it seems that subtlety got lost in > the process of fitting it into the differently-shaped control flow, and > as a result the force_dma==true case ends up always setting the bus mask > to the 32-bit default, which is not what anyone wants. > > Make sure we only touch it if the DT actually said so. This looks good, but I think it could really use a comment as the use of ret all the way down the function isn't exactly obvious. Let me now if you want this picked up through the OF or DMA trees. From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 07 Nov 2018 09:04:15 +0100 (CET) Received: from verein.lst.de ([213.95.11.211]:36341 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S23990946AbeKGIDgfMUlZ (ORCPT ); Wed, 7 Nov 2018 09:03:36 +0100 Received: by newverein.lst.de (Postfix, from userid 2407) id 01BC968C44; Wed, 7 Nov 2018 09:03:36 +0100 (CET) Date: Wed, 7 Nov 2018 09:03:35 +0100 From: Christoph Hellwig To: Robin Murphy Cc: hch@lst.de, robh+dt@kernel.org, m.szyprowski@samsung.com, aaro.koskinen@iki.fi, jean-philippe.brucker@arm.com, john.stultz@linaro.org, iommu@lists.linux-foundation.org, devicetree@vger.kernel.org, linux-mips@linux-mips.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] of/device: Really only set bus DMA mask when appropriate Message-ID: <20181107080335.GA24511@lst.de> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 67122 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: hch@lst.de Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On Tue, Nov 06, 2018 at 11:54:15AM +0000, Robin Murphy wrote: > of_dma_configure() was *supposed* to be following the same logic as > acpi_dma_configure() and only setting bus_dma_mask if some range was > specified by the firmware. However, it seems that subtlety got lost in > the process of fitting it into the differently-shaped control flow, and > as a result the force_dma==true case ends up always setting the bus mask > to the 32-bit default, which is not what anyone wants. > > Make sure we only touch it if the DT actually said so. This looks good, but I think it could really use a comment as the use of ret all the way down the function isn't exactly obvious. Let me now if you want this picked up through the OF or DMA trees. From mboxrd@z Thu Jan 1 00:00:00 1970 From: hch@lst.de (Christoph Hellwig) Date: Wed, 7 Nov 2018 09:03:35 +0100 Subject: [PATCH] of/device: Really only set bus DMA mask when appropriate In-Reply-To: References: Message-ID: <20181107080335.GA24511@lst.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Nov 06, 2018 at 11:54:15AM +0000, Robin Murphy wrote: > of_dma_configure() was *supposed* to be following the same logic as > acpi_dma_configure() and only setting bus_dma_mask if some range was > specified by the firmware. However, it seems that subtlety got lost in > the process of fitting it into the differently-shaped control flow, and > as a result the force_dma==true case ends up always setting the bus mask > to the 32-bit default, which is not what anyone wants. > > Make sure we only touch it if the DT actually said so. This looks good, but I think it could really use a comment as the use of ret all the way down the function isn't exactly obvious. Let me now if you want this picked up through the OF or DMA trees.