[RFC 07/13] v4l: vb2-dma-contig: change map/unmap behaviour for importers

The DMABUF documentation says that the map_dma_buf callback should return scatterlist that is mapped into a caller's address space. In practice, almost none of existing implementations of DMABUF exporter does it. This patch breaks the DMABUF specification in order to allow exchange DMABUF buffers

[RFC 07/13] v4l: vb2-dma-contig: change map/unmap behaviour for importers

The DMABUF documentation says that the map_dma_buf callback should return scatterlist that is mapped into a caller's address space. In practice, almost none of existing implementations of DMABUF exporter does it. This patch breaks the DMABUF specification in order to allow exchange DMABUF buffers