From mboxrd@z Thu Jan  1 00:00:00 1970
From: robin.murphy@arm.com (Robin Murphy)
Date: Wed, 10 Jan 2018 17:23:08 +0000
Subject: [PATCH 08/22] swiotlb: wire up ->dma_supported in swiotlb_dma_ops
In-Reply-To: <20180110153517.GF17790@lst.de>
References: <20180110080932.14157-1-hch@lst.de>
 <20180110080932.14157-9-hch@lst.de>
 <7a058876-08fc-7323-7cb3-fe85116e2ea8@arm.com>
 <20180110153517.GF17790@lst.de>
Message-ID: <5b14af5b-e6e9-17c5-d433-f50ccb466f90@arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: 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.