From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Murphy Date: Wed, 10 Jan 2018 17:23:08 +0000 Subject: Re: [PATCH 08/22] swiotlb: wire up ->dma_supported in swiotlb_dma_ops Message-Id: <5b14af5b-e6e9-17c5-d433-f50ccb466f90@arm.com> List-Id: References: <20180110080932.14157-1-hch@lst.de> <20180110080932.14157-9-hch@lst.de> <7a058876-08fc-7323-7cb3-fe85116e2ea8@arm.com> <20180110153517.GF17790@lst.de> In-Reply-To: <20180110153517.GF17790@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Christoph Hellwig Cc: iommu@lists.linux-foundation.org, linux-arch@vger.kernel.org, linux-mips@linux-mips.org, Michal Simek , linux-ia64@vger.kernel.org, =?UTF-8?Q?Christian_K=c3=b6nig?= , x86@kernel.org, linux-kernel@vger.kernel.org, Konrad Rzeszutek Wilk , Guan Xuetao , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org On 10/01/18 15:35, Christoph Hellwig wrote: > On Wed, Jan 10, 2018 at 12:16:15PM +0000, Robin Murphy wrote: >> On 10/01/18 08:09, Christoph Hellwig wrote: >>> To properly reject too small DMA masks based on the addressability of the >>> bounce buffer. >> >> I reckon this is self-evident enough that it should simply be squashed into >> the previous patch. > > x86 didn't wire it up before, so I want a clear blaimpoint for this > change instead of mixing it up. That almost makes sense, if x86 were using this generic swiotlb_dma_ops already. AFAICS it's only ia64, unicore and tile who end up using it, and they all had swiotlb_dma_supported hooked up to begin with. Am I missing something? If regressions are going to happen, they'll surely point at whichever commit pulls the ops into the relevant arch code - there doesn't seem to be a great deal of value in having a piecemeal history of said ops *before* that point. Robin.