5680fe45d6
The media_entity_remote_pad_first() helper function returns the first remote pad it finds connected to a given pad. Beside being possibly non-deterministic (as it stops at the first enabled link), the fact that it returns the first match makes it unsuitable for drivers that need to guarantee that a single link is enabled, for instance when an entity can process data from one of multiple sources at a time. For those use cases, add a new helper function, media_entity_remote_pad_unique(), that operates on an entity and returns a remote pad, with a guarantee that only one link is enabled. To ease its use in drivers, also add an inline wrapper that locates source pads specifically. A wrapper that locates sink pads can easily be added when needed. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.