Files
android_kernel_xiaomi_sm8450/Documentation/userspace-api/media/dvb/fe-read-ber.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_READ_BER:
***********
FE_READ_BER
***********
Name
====
FE_READ_BER
.. attention:: This ioctl is deprecated.
Synopsis
========
.. c:function:: int ioctl(int fd, FE_READ_BER, uint32_t *ber)
:name: FE_READ_BER
Arguments
=========
``fd``
File descriptor returned by :c:func:`open() <dvb-fe-open>`.
``ber``
The bit error rate is stored into \*ber.
Description
===========
This ioctl call returns the bit error rate for the signal currently
received/demodulated by the front-end. For this command, read-only
access to the device is sufficient.
Return Value
============
On success 0 is returned.
On error -1 is returned, and the ``errno`` variable is set
appropriately.
Generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.