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
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.. c:namespace:: MC
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.. _media_request_ioc_reinit:
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******************************
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ioctl MEDIA_REQUEST_IOC_REINIT
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******************************
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Name
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====
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MEDIA_REQUEST_IOC_REINIT - Re-initialize a request
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Synopsis
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========
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.. c:macro:: MEDIA_REQUEST_IOC_REINIT
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``int ioctl(int request_fd, MEDIA_REQUEST_IOC_REINIT)``
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Arguments
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=========
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``request_fd``
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File descriptor returned by :ref:`MEDIA_IOC_REQUEST_ALLOC`.
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Description
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===========
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If the media device supports :ref:`requests <media-request-api>`, then
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this request ioctl can be used to re-initialize a previously allocated
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request.
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Re-initializing a request will clear any existing data from the request.
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This avoids having to :c:func:`close()` a completed
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request and allocate a new request. Instead the completed request can just
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be re-initialized and it is ready to be used again.
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A request can only be re-initialized if it either has not been queued
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yet, or if it was queued and completed. Otherwise it will set ``errno``
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to ``EBUSY``. No other error codes can be returned.
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Return Value
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============
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On success 0 is returned, on error -1 and the ``errno`` variable is set
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appropriately.
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EBUSY
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The request is queued but not yet completed.
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