[Linaro-mm-sig] [RFC] dma-shared-buf: Add buffer sharing framework

[Michael K. Edwards]

On Mon, Aug 29, 2011 at 10:16 PM, Subash Patel <subashrp at gmail.com> wrote:
> Your use case of blocking on read() can be helpful only for a movie
> thumbnail in gallery. Otherwise, blocking on read(fd) in a userspace can
> result in frame loss during the encode kind of operation.

Yes, that's exactly the kind of use case I had in mind.  Similarly,
frame-grab from userland on a pipeline whose continuous flow is
in-kernel.  The argument is not that you shouldn't have mmap(), it's
that you should also have read(), because there are use cases for it.

- M