IMX Scaler / CSC m2m driver.

[Ian Molton]

On 20/03/15 16:46, Nicolas Dufresne wrote:
> Wrong, USERPTR is also a importing role. Certain driver, like UVC, can
> deal with vmalloc memory, and write directly from USB port to it. So using:
>
> v4l2src io-mode=userptr ! xvimagesink
>
> Actually saves a copy. Note that some driver support USERPTR, but fails
> if the memory isn't contiguous or page aligned.

ah, ok. then this implies a bug in videobuf2?, since:

(from the coda driver)

         src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
         src_vq->io_modes = VB2_DMABUF | VB2_MMAP | VB2_USERPTR;
         src_vq->mem_ops = &vb2_vmalloc_memops;

I'll try to trace through calls via vb2_vmalloc_memops.* tomorrow.

-Ian