Re: [PATCH 3/3] videobuf2: replace a layering violation with dma_map_resource

[Christoph Hellwig]

On Fri, Jan 11, 2019 at 05:54:16PM -0200, Mauro Carvalho Chehab wrote:
> Em Fri, 11 Jan 2019 19:17:31 +0100
> Christoph Hellwig <hch@xxxxxx> escreveu:
> 
> > vb2_dc_get_userptr pokes into arm direct mapping details to get the
> > resemblance of a dma address for a a physical address that does is
> > not backed by a page struct.  Not only is this not portable to other
> > architectures with dma direct mapping offsets, but also not to uses
> > of IOMMUs of any kind.  Switch to the proper dma_map_resource /
> > dma_unmap_resource interface instead.
> 
> Makes sense to me. I'm assuming that you'll be pushing it together
> with other mm patches, so:

Not really mm, but rather DMA mapping, but yes, I'd love to take it
all together.

Thanks!