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diff --git a/Documentation/media/uapi/v4l/vidioc-streamon.rst b/Documentation/media/uapi/v4l/vidioc-streamon.rst deleted file mode 100644 index 2b5528ec9f89..000000000000 --- a/Documentation/media/uapi/v4l/vidioc-streamon.rst +++ /dev/null @@ -1,113 +0,0 @@ -.. 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/media/uapi/fdl-appendix.rst. -.. -.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections - -.. _VIDIOC_STREAMON: - -*************************************** -ioctl VIDIOC_STREAMON, VIDIOC_STREAMOFF -*************************************** - -Name -==== - -VIDIOC_STREAMON - VIDIOC_STREAMOFF - Start or stop streaming I/O - - -Synopsis -======== - -.. c:function:: int ioctl( int fd, VIDIOC_STREAMON, const int *argp ) - :name: VIDIOC_STREAMON - -.. c:function:: int ioctl( int fd, VIDIOC_STREAMOFF, const int *argp ) - :name: VIDIOC_STREAMOFF - - -Arguments -========= - -``fd`` - File descriptor returned by :ref:`open() <func-open>`. - -``argp`` - Pointer to an integer. - -Description -=========== - -The ``VIDIOC_STREAMON`` and ``VIDIOC_STREAMOFF`` ioctl start and stop -the capture or output process during streaming -(:ref:`memory mapping <mmap>`, :ref:`user pointer <userp>` or -:ref:`DMABUF <dmabuf>`) I/O. - -Capture hardware is disabled and no input buffers are filled (if there -are any empty buffers in the incoming queue) until ``VIDIOC_STREAMON`` -has been called. Output hardware is disabled and no video signal is -produced until ``VIDIOC_STREAMON`` has been called. The ioctl will -succeed when at least one output buffer is in the incoming queue. - -Memory-to-memory devices will not start until ``VIDIOC_STREAMON`` has -been called for both the capture and output stream types. - -If ``VIDIOC_STREAMON`` fails then any already queued buffers will remain -queued. - -The ``VIDIOC_STREAMOFF`` ioctl, apart of aborting or finishing any DMA -in progress, unlocks any user pointer buffers locked in physical memory, -and it removes all buffers from the incoming and outgoing queues. That -means all images captured but not dequeued yet will be lost, likewise -all images enqueued for output but not transmitted yet. I/O returns to -the same state as after calling -:ref:`VIDIOC_REQBUFS` and can be restarted -accordingly. - -If buffers have been queued with :ref:`VIDIOC_QBUF` and -``VIDIOC_STREAMOFF`` is called without ever having called -``VIDIOC_STREAMON``, then those queued buffers will also be removed from -the incoming queue and all are returned to the same state as after -calling :ref:`VIDIOC_REQBUFS` and can be restarted -accordingly. - -Both ioctls take a pointer to an integer, the desired buffer or stream -type. This is the same as struct -:c:type:`v4l2_requestbuffers` ``type``. - -If ``VIDIOC_STREAMON`` is called when streaming is already in progress, -or if ``VIDIOC_STREAMOFF`` is called when streaming is already stopped, -then 0 is returned. Nothing happens in the case of ``VIDIOC_STREAMON``, -but ``VIDIOC_STREAMOFF`` will return queued buffers to their starting -state as mentioned above. - -.. note:: - - Applications can be preempted for unknown periods right before - or after the ``VIDIOC_STREAMON`` or ``VIDIOC_STREAMOFF`` calls, there is - no notion of starting or stopping "now". Buffer timestamps can be used - to synchronize with other events. - - -Return Value -============ - -On success 0 is returned, on error -1 and the ``errno`` variable is set -appropriately. The generic error codes are described at the -:ref:`Generic Error Codes <gen-errors>` chapter. - -EINVAL - The buffer ``type`` is not supported, or no buffers have been - allocated (memory mapping) or enqueued (output) yet. - -EPIPE - The driver implements - :ref:`pad-level format configuration <pad-level-formats>` and the - pipeline configuration is invalid. - -ENOLINK - The driver implements Media Controller interface and the pipeline - link configuration is invalid. |