f729ef5796
If a driver calls (_)vb2_fop_release(), then such a driver should also call vb2_video_unregister_device() instead of video_unregister_device(). This helper will call vb2_queue_release() if a filehandle is marked as owner of the queue. This ensures that at unregister time any streaming is cancelled and all buffers are returned to userspace. This is very useful for complex drivers since this stops all streaming in all subdevs in the pipeline controlled by this video device. Otherwise this would be delayed until the owner filehandle is closed, which can be quite some time later. Bonus points for ordering the includes :-) Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@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.