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linux-next/Documentation/userspace-api/media/dvb/fe-get-event.rst
Mauro Carvalho Chehab 54f38fcae5 media: docs: move uAPI book to userspace-api/media
Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee38 ("docs: Create a user-space API guide").

As the media subsystem was one of the first subsystems to use
Sphinx, until this patch, we were keeping things on a separate
place.

Let's just use the new location, as having all uAPI altogether
will likely make things easier for developers.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-14 10:31:49 +02:00

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.. Permission is granted to copy, distribute and/or modify this
.. document under the terms of the GNU Free Documentation License,
.. Version 1.1 or any later version published by the Free Software
.. Foundation, with no Invariant Sections, no Front-Cover Texts
.. and no Back-Cover Texts. A copy of the license is included at
.. Documentation/userspace-api/media/fdl-appendix.rst.
..
.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
.. _FE_GET_EVENT:
************
FE_GET_EVENT
************
Name
====
FE_GET_EVENT
.. attention:: This ioctl is deprecated.
Synopsis
========
.. c:function:: int ioctl(int fd, FE_GET_EVENT, struct dvb_frontend_event *ev)
:name: FE_GET_EVENT
Arguments
=========
``fd``
File descriptor returned by :c:func:`open() <dvb-fe-open>`.
``ev``
Points to the location where the event, if any, is to be stored.
Description
===========
This ioctl call returns a frontend event if available. If an event is
not available, the behavior depends on whether the device is in blocking
or non-blocking mode. In the latter case, the call fails immediately
with errno set to ``EWOULDBLOCK``. In the former case, the call blocks until
an event becomes available.
Return Value
============
On success 0 is returned.
On error -1 is returned, and the ``errno`` variable is set
appropriately.
.. flat-table::
:header-rows: 0
:stub-columns: 0
- .. row 1
- ``EWOULDBLOCK``
- There is no event pending, and the device is in non-blocking mode.
- .. row 2
- ``EOVERFLOW``
- Overflow in event queue - one or more events were lost.
Generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.