Re: [PATCH 08/22] swiotlb: wire up ->dma_supported in swiotlb_dma_ops

Robin Murphy
2018-01-10T17:23:15Z

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.