[PATCH v4 14/36] [media] v4l2-mc: add a function to inherit controls from a pipeline

On Fri, 2017-03-17 at 10:24 -0300, Mauro Carvalho Chehab wrote:
[...]

The big question, waiting for an answer on the last 8 years is
who would do that? Such person would need to have several different
hardware from different vendors, in order to ensure that it has
a generic solution.

It is a way more feasible that the Kernel developers that already 
have a certain hardware on their hands to add support inside the
driver to forward the controls through the pipeline and to setup
a "default" pipeline that would cover the common use cases at
driver's probe.

Actually, would setting pipeline via libv4l2 plugin and letting drivers
provide a sane enabled default pipeline configuration be mutually
exclusive? Not sure about the control forwarding, but at least a simple
link setup and format forwarding would also be possible in the kernel
without hindering userspace from doing it themselves later.

regards
Philipp