Re: [PATCH] media: uvcvideo: Use streaming DMA APIs to transfer buffers

[Christoph Hellwig]

On Mon, Sep 30, 2019 at 01:23:10AM -0700, Christoph Hellwig wrote:
> And drivers really have no business looking at the dma mask.  I have
> a plan for dma_alloc_pages API that could replace that cruft, but
> until then please use GFP_KERNEL and let the dma subsystem bounce
> buffer if needed.

Can you try this series:

http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/dma_alloc_pages

and see if it does whay you need for usb?