mirror of https://gitee.com/openkylin/linux.git
52 lines
1.3 KiB
ReStructuredText
52 lines
1.3 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later
|
|
|
|
.. _media_request_ioc_reinit:
|
|
|
|
******************************
|
|
ioctl MEDIA_REQUEST_IOC_REINIT
|
|
******************************
|
|
|
|
Name
|
|
====
|
|
|
|
MEDIA_REQUEST_IOC_REINIT - Re-initialize a request
|
|
|
|
|
|
Synopsis
|
|
========
|
|
|
|
.. c:function:: int ioctl( int request_fd, MEDIA_REQUEST_IOC_REINIT )
|
|
:name: MEDIA_REQUEST_IOC_REINIT
|
|
|
|
|
|
Arguments
|
|
=========
|
|
|
|
``request_fd``
|
|
File descriptor returned by :ref:`MEDIA_IOC_REQUEST_ALLOC`.
|
|
|
|
Description
|
|
===========
|
|
|
|
If the media device supports :ref:`requests <media-request-api>`, then
|
|
this request ioctl can be used to re-initialize a previously allocated
|
|
request.
|
|
|
|
Re-initializing a request will clear any existing data from the request.
|
|
This avoids having to :ref:`close() <request-func-close>` a completed
|
|
request and allocate a new request. Instead the completed request can just
|
|
be re-initialized and it is ready to be used again.
|
|
|
|
A request can only be re-initialized if it either has not been queued
|
|
yet, or if it was queued and completed. Otherwise it will set ``errno``
|
|
to ``EBUSY``. No other error codes can be returned.
|
|
|
|
Return Value
|
|
============
|
|
|
|
On success 0 is returned, on error -1 and the ``errno`` variable is set
|
|
appropriately.
|
|
|
|
EBUSY
|
|
The request is queued but not yet completed.
|