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: devicetree@vger.kernel.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.