diff --git a/Documentation/linux_tv/media/dvb/frontend_f_open.rst b/Documentation/linux_tv/media/dvb/frontend_f_open.rst index ba9fbb17f70d336464749ab45520abfa7e7392c5..d28c64514433911dcbaae7e6730dcf4c438c3795 100644 --- a/Documentation/linux_tv/media/dvb/frontend_f_open.rst +++ b/Documentation/linux_tv/media/dvb/frontend_f_open.rst @@ -72,8 +72,9 @@ that possible. Return Value ============ -On success :c:func:`open()` returns the new file descriptor. On error --1 is returned, and the ``errno`` variable is set appropriately. +On success :ref:`open() ` returns the new file descriptor. +On error, -1 is returned, and the ``errno`` variable is set appropriately. + Possible error codes are: EACCES diff --git a/Documentation/linux_tv/media/v4l/dmabuf.rst b/Documentation/linux_tv/media/v4l/dmabuf.rst index cd68f755c0e39d64944a68662996ba04a882295f..ae1bd2dfc61e93c560d1428786f9db3f7abea11d 100644 --- a/Documentation/linux_tv/media/v4l/dmabuf.rst +++ b/Documentation/linux_tv/media/v4l/dmabuf.rst @@ -146,4 +146,4 @@ outputted buffers. Drivers implementing DMABUF importing I/O must support the ``VIDIOC_REQBUFS``, ``VIDIOC_QBUF``, ``VIDIOC_DQBUF``, ``VIDIOC_STREAMON`` and ``VIDIOC_STREAMOFF`` ioctls, and the -:c:func:`select()` and :c:func:`poll()` functions. +:ref:`select() ` and :ref:`poll() ` functions. diff --git a/Documentation/linux_tv/media/v4l/func-ioctl.rst b/Documentation/linux_tv/media/v4l/func-ioctl.rst index d442d9b56dfb32da01f2118edce7d0160fe69b04..fafec5f56a36596f3852da4a2d9d7b4fca4cbca9 100644 --- a/Documentation/linux_tv/media/v4l/func-ioctl.rst +++ b/Documentation/linux_tv/media/v4l/func-ioctl.rst @@ -38,7 +38,7 @@ Arguments Description =========== -The :c:func:`ioctl()` function is used to program V4L2 devices. The +The :ref:`ioctl() ` function is used to program V4L2 devices. The argument ``fd`` must be an open file descriptor. An ioctl ``request`` has encoded in it whether the argument is an input, output or read/write parameter, and the size of the argument ``argp`` in bytes. Macros and diff --git a/Documentation/linux_tv/media/v4l/func-mmap.rst b/Documentation/linux_tv/media/v4l/func-mmap.rst index a0be2d9b5421c639b43fafe780aaad558f7b3b6a..345ac3005c8f5004fce68db36978918353ded69a 100644 --- a/Documentation/linux_tv/media/v4l/func-mmap.rst +++ b/Documentation/linux_tv/media/v4l/func-mmap.rst @@ -49,7 +49,7 @@ Arguments module, which is used by the bttv, saa7134, saa7146, cx88 and vivi driver supports only ``PROT_READ`` | ``PROT_WRITE``. When the driver does not support the desired protection the - :c:func:`mmap()` function fails. + :ref:`mmap() ` function fails. Note device memory accesses (e. g. the memory on a graphics card with video capturing hardware) may incur a performance penalty @@ -65,7 +65,7 @@ Arguments ``MAP_FIXED`` requests that the driver selects no other address than the one specified. If the specified address cannot be used, - :c:func:`mmap()` will fail. If ``MAP_FIXED`` is specified, + :ref:`mmap() ` will fail. If ``MAP_FIXED`` is specified, ``start`` must be a multiple of the pagesize. Use of this option is discouraged. @@ -92,7 +92,7 @@ Arguments Description =========== -The :c:func:`mmap()` function asks to map ``length`` bytes starting at +The :ref:`mmap() ` function asks to map ``length`` bytes starting at ``offset`` in the memory of the device specified by ``fd`` into the application address space, preferably at address ``start``. This latter address is a hint only, and is usually specified as 0. @@ -108,7 +108,7 @@ To unmap buffers the :ref:`munmap() ` function is used. Return Value ============ -On success :c:func:`mmap()` returns a pointer to the mapped buffer. On +On success :ref:`mmap() ` returns a pointer to the mapped buffer. On error ``MAP_FAILED`` (-1) is returned, and the ``errno`` variable is set appropriately. Possible error codes are: diff --git a/Documentation/linux_tv/media/v4l/func-munmap.rst b/Documentation/linux_tv/media/v4l/func-munmap.rst index 1f9831795db759c9c80eb9b3fba3f64d6e78af60..f87eb387f499d008e8a39e11bc674f9575c2dc2f 100644 --- a/Documentation/linux_tv/media/v4l/func-munmap.rst +++ b/Documentation/linux_tv/media/v4l/func-munmap.rst @@ -31,7 +31,7 @@ Arguments ``length`` Length of the mapped buffer. This must be the same value as given to - :c:func:`mmap()` and returned by the driver in the struct + :ref:`mmap() ` and returned by the driver in the struct :ref:`v4l2_buffer ` ``length`` field for the single-planar API and in the struct :ref:`v4l2_plane ` ``length`` field for the @@ -48,7 +48,7 @@ buffer and frees it, if possible. Return Value ============ -On success :c:func:`munmap()` returns 0, on failure -1 and the +On success :ref:`munmap() ` returns 0, on failure -1 and the ``errno`` variable is set appropriately: EINVAL diff --git a/Documentation/linux_tv/media/v4l/func-open.rst b/Documentation/linux_tv/media/v4l/func-open.rst index c021772a9deeadcb32ba2cc48f654158394ca0c9..9598c0fd592e6e1ce852c8741b937e286778ff34 100644 --- a/Documentation/linux_tv/media/v4l/func-open.rst +++ b/Documentation/linux_tv/media/v4l/func-open.rst @@ -45,10 +45,10 @@ Arguments Description =========== -To open a V4L2 device applications call :c:func:`open()` with the +To open a V4L2 device applications call :ref:`open() ` with the desired device name. This function has no side effects; all data format parameters, current input or output, control values or other properties -remain unchanged. At the first :c:func:`open()` call after loading the +remain unchanged. At the first :ref:`open() ` call after loading the driver they will be reset to default values, drivers are never in an undefined state. @@ -56,7 +56,7 @@ undefined state. Return Value ============ -On success :c:func:`open()` returns the new file descriptor. On error +On success :ref:`open() ` returns the new file descriptor. On error -1 is returned, and the ``errno`` variable is set appropriately. Possible error codes are: diff --git a/Documentation/linux_tv/media/v4l/func-poll.rst b/Documentation/linux_tv/media/v4l/func-poll.rst index bfbcec2bb0cd69e2b6bb1fe8ab821269230d54bc..27f381d75de18c75a1d24b162f5adf8b7302dfc5 100644 --- a/Documentation/linux_tv/media/v4l/func-poll.rst +++ b/Documentation/linux_tv/media/v4l/func-poll.rst @@ -24,7 +24,7 @@ Synopsis Description =========== -With the :c:func:`poll()` function applications can suspend execution +With the :ref:`poll() ` function applications can suspend execution until the driver has captured data or is ready to accept data for output. @@ -37,7 +37,7 @@ display. When buffers are already in the outgoing queue of the driver (capture) or the incoming queue isn't full (display) the function returns immediately. -On success :c:func:`poll()` returns the number of file descriptors +On success :ref:`poll() ` returns the number of file descriptors that have been selected (that is, file descriptors for which the ``revents`` field of the respective :c:func:`struct pollfd` structure is non-zero). Capture devices set the ``POLLIN`` and ``POLLRDNORM`` @@ -45,49 +45,49 @@ flags in the ``revents`` field, output devices the ``POLLOUT`` and ``POLLWRNORM`` flags. When the function timed out it returns a value of zero, on failure it returns -1 and the ``errno`` variable is set appropriately. When the application did not call -:ref:`VIDIOC_STREAMON` the :c:func:`poll()` +:ref:`VIDIOC_STREAMON` the :ref:`poll() ` function succeeds, but sets the ``POLLERR`` flag in the ``revents`` field. When the application has called :ref:`VIDIOC_STREAMON` for a capture device but hasn't yet called :ref:`VIDIOC_QBUF`, the -:c:func:`poll()` function succeeds and sets the ``POLLERR`` flag in +:ref:`poll() ` function succeeds and sets the ``POLLERR`` flag in the ``revents`` field. For output devices this same situation will cause -:c:func:`poll()` to succeed as well, but it sets the ``POLLOUT`` and +:ref:`poll() ` to succeed as well, but it sets the ``POLLOUT`` and ``POLLWRNORM`` flags in the ``revents`` field. If an event occurred (see :ref:`VIDIOC_DQEVENT`) then ``POLLPRI`` will be set in the ``revents`` field and -:c:func:`poll()` will return. +:ref:`poll() ` will return. -When use of the :c:func:`read()` function has been negotiated and the -driver does not capture yet, the :c:func:`poll()` function starts +When use of the :ref:`read() ` function has been negotiated and the +driver does not capture yet, the :ref:`poll() ` function starts capturing. When that fails it returns a ``POLLERR`` as above. Otherwise it waits until data has been captured and can be read. When the driver captures continuously (as opposed to, for example, still images) the function may return immediately. -When use of the :c:func:`write()` function has been negotiated and the -driver does not stream yet, the :c:func:`poll()` function starts +When use of the :ref:`write() ` function has been negotiated and the +driver does not stream yet, the :ref:`poll() ` function starts streaming. When that fails it returns a ``POLLERR`` as above. Otherwise it waits until the driver is ready for a non-blocking -:c:func:`write()` call. +:ref:`write() ` call. If the caller is only interested in events (just ``POLLPRI`` is set in -the ``events`` field), then :c:func:`poll()` will *not* start +the ``events`` field), then :ref:`poll() ` will *not* start streaming if the driver does not stream yet. This makes it possible to just poll for events and not for buffers. -All drivers implementing the :c:func:`read()` or :c:func:`write()` -function or streaming I/O must also support the :c:func:`poll()` +All drivers implementing the :ref:`read() ` or :ref:`write() ` +function or streaming I/O must also support the :ref:`poll() ` function. -For more details see the :c:func:`poll()` manual page. +For more details see the :ref:`poll() ` manual page. Return Value ============ -On success, :c:func:`poll()` returns the number structures which have +On success, :ref:`poll() ` returns the number structures which have non-zero ``revents`` fields, or zero if the call timed out. On error -1 is returned, and the ``errno`` variable is set appropriately: diff --git a/Documentation/linux_tv/media/v4l/func-read.rst b/Documentation/linux_tv/media/v4l/func-read.rst index 9238ecddec72525bfa20a10e8f4fd1859ebfb6e2..75985f664da7079e5b33b6ccfeb972decd4f433b 100644 --- a/Documentation/linux_tv/media/v4l/func-read.rst +++ b/Documentation/linux_tv/media/v4l/func-read.rst @@ -34,48 +34,48 @@ Arguments Description =========== -:c:func:`read()` attempts to read up to ``count`` bytes from file +:ref:`read() ` attempts to read up to ``count`` bytes from file descriptor ``fd`` into the buffer starting at ``buf``. The layout of the data in the buffer is discussed in the respective device interface -section, see ##. If ``count`` is zero, :c:func:`read()` returns zero +section, see ##. If ``count`` is zero, :ref:`read() ` returns zero and has no other results. If ``count`` is greater than ``SSIZE_MAX``, the result is unspecified. Regardless of the ``count`` value each -:c:func:`read()` call will provide at most one frame (two fields) +:ref:`read() ` call will provide at most one frame (two fields) worth of data. -By default :c:func:`read()` blocks until data becomes available. When +By default :ref:`read() ` blocks until data becomes available. When the ``O_NONBLOCK`` flag was given to the :ref:`open() ` function it returns immediately with an ``EAGAIN`` error code when no data is available. The :ref:`select() ` or :ref:`poll() ` functions can always be used to suspend execution until data becomes available. All drivers supporting the -:c:func:`read()` function must also support :c:func:`select()` and -:c:func:`poll()`. +:ref:`read() ` function must also support :ref:`select() ` and +:ref:`poll() `. Drivers can implement read functionality in different ways, using a single or multiple buffers and discarding the oldest or newest frames once the internal buffers are filled. -:c:func:`read()` never returns a "snapshot" of a buffer being filled. +:ref:`read() ` never returns a "snapshot" of a buffer being filled. Using a single buffer the driver will stop capturing when the application starts reading the buffer until the read is finished. Thus only the period of the vertical blanking interval is available for reading, or the capture rate must fall below the nominal frame rate of the video standard. -The behavior of :c:func:`read()` when called during the active picture +The behavior of :ref:`read() ` when called during the active picture period or the vertical blanking separating the top and bottom field depends on the discarding policy. A driver discarding the oldest frames keeps capturing into an internal buffer, continuously overwriting the previously, not read frame, and returns the frame being received at the -time of the :c:func:`read()` call as soon as it is complete. +time of the :ref:`read() ` call as soon as it is complete. A driver discarding the newest frames stops capturing until the next -:c:func:`read()` call. The frame being received at :c:func:`read()` +:ref:`read() ` call. The frame being received at :ref:`read() ` time is discarded, returning the following frame instead. Again this implies a reduction of the capture rate to one half or less of the nominal frame rate. An example of this model is the video read mode of -the bttv driver, initiating a DMA to user memory when :c:func:`read()` +the bttv driver, initiating a DMA to user memory when :ref:`read() ` is called and returning when the DMA finished. In the multiple buffer model drivers maintain a ring of internal @@ -97,7 +97,7 @@ Return Value On success, the number of bytes read is returned. It is not an error if this number is smaller than the number of bytes requested, or the amount of data required for one frame. This may happen for example because -:c:func:`read()` was interrupted by a signal. On error, -1 is +:ref:`read() ` was interrupted by a signal. On error, -1 is returned, and the ``errno`` variable is set appropriately. In this case the next read will start at the beginning of a new frame. Possible error codes are: @@ -125,5 +125,5 @@ EIO communicate with a remote device (USB camera etc.). EINVAL - The :c:func:`read()` function is not supported by this driver, not + The :ref:`read() ` function is not supported by this driver, not on this device, or generally not on this type of device. diff --git a/Documentation/linux_tv/media/v4l/func-select.rst b/Documentation/linux_tv/media/v4l/func-select.rst index 5f2ff6a5e00cd46af70dd4de2f0cf785e0d64a68..57089f5cc6cd9dadcf7e16c8433a0f20c3548352 100644 --- a/Documentation/linux_tv/media/v4l/func-select.rst +++ b/Documentation/linux_tv/media/v4l/func-select.rst @@ -26,7 +26,7 @@ Synopsis Description =========== -With the :c:func:`select()` function applications can suspend +With the :ref:`select() ` function applications can suspend execution until the driver has captured data or is ready to accept data for output. @@ -35,40 +35,40 @@ buffer has been filled or displayed and can be dequeued with the :ref:`VIDIOC_DQBUF ` ioctl. When buffers are already in the outgoing queue of the driver the function returns immediately. -On success :c:func:`select()` returns the total number of bits set in +On success :ref:`select() ` returns the total number of bits set in :c:func:`struct fd_set`. When the function timed out it returns a value of zero. On failure it returns -1 and the ``errno`` variable is set appropriately. When the application did not call :ref:`VIDIOC_QBUF` or -:ref:`VIDIOC_STREAMON` yet the :c:func:`select()` +:ref:`VIDIOC_STREAMON` yet the :ref:`select() ` function succeeds, setting the bit of the file descriptor in ``readfds`` or ``writefds``, but subsequent :ref:`VIDIOC_DQBUF ` calls will fail. [1]_ -When use of the :c:func:`read()` function has been negotiated and the -driver does not capture yet, the :c:func:`select()` function starts -capturing. When that fails, :c:func:`select()` returns successful and -a subsequent :c:func:`read()` call, which also attempts to start +When use of the :ref:`read() ` function has been negotiated and the +driver does not capture yet, the :ref:`select() ` function starts +capturing. When that fails, :ref:`select() ` returns successful and +a subsequent :ref:`read() ` call, which also attempts to start capturing, will return an appropriate error code. When the driver captures continuously (as opposed to, for example, still images) and -data is already available the :c:func:`select()` function returns +data is already available the :ref:`select() ` function returns immediately. -When use of the :c:func:`write()` function has been negotiated the -:c:func:`select()` function just waits until the driver is ready for a -non-blocking :c:func:`write()` call. +When use of the :ref:`write() ` function has been negotiated the +:ref:`select() ` function just waits until the driver is ready for a +non-blocking :ref:`write() ` call. -All drivers implementing the :c:func:`read()` or :c:func:`write()` -function or streaming I/O must also support the :c:func:`select()` +All drivers implementing the :ref:`read() ` or :ref:`write() ` +function or streaming I/O must also support the :ref:`select() ` function. -For more details see the :c:func:`select()` manual page. +For more details see the :ref:`select() ` manual page. Return Value ============ -On success, :c:func:`select()` returns the number of descriptors +On success, :ref:`select() ` returns the number of descriptors contained in the three returned descriptor sets, which will be zero if the timeout expired. On error -1 is returned, and the ``errno`` variable is set appropriately; the sets and ``timeout`` are undefined. Possible @@ -94,6 +94,6 @@ EINVAL ``FD_SETSIZE``. .. [1] - The Linux kernel implements :c:func:`select()` like the - :ref:`poll() ` function, but :c:func:`select()` cannot + The Linux kernel implements :ref:`select() ` like the + :ref:`poll() ` function, but :ref:`select() ` cannot return a ``POLLERR``. diff --git a/Documentation/linux_tv/media/v4l/func-write.rst b/Documentation/linux_tv/media/v4l/func-write.rst index fee5fe004c0a004d5f2d6f0f2bd23ac9fb68c283..a4b093ba15c37cf635806b1f33f229e14b88a9dc 100644 --- a/Documentation/linux_tv/media/v4l/func-write.rst +++ b/Documentation/linux_tv/media/v4l/func-write.rst @@ -34,10 +34,10 @@ Arguments Description =========== -:c:func:`write()` writes up to ``count`` bytes to the device +:ref:`write() ` writes up to ``count`` bytes to the device referenced by the file descriptor ``fd`` from the buffer starting at ``buf``. When the hardware outputs are not active yet, this function -enables them. When ``count`` is zero, :c:func:`write()` returns 0 +enables them. When ``count`` is zero, :ref:`write() ` returns 0 without any other effect. When the application does not provide more data in time, the previous @@ -76,5 +76,5 @@ EIO I/O error. This indicates some hardware problem. EINVAL - The :c:func:`write()` function is not supported by this driver, + The :ref:`write() ` function is not supported by this driver, not on this device, or generally not on this type of device. diff --git a/Documentation/linux_tv/media/v4l/io.rst b/Documentation/linux_tv/media/v4l/io.rst index e68342606ed39cb68e9f4ba44ea8e3e1e86f7c62..94b38a10ee658dbd4208d33485d60a48ac42bb91 100644 --- a/Documentation/linux_tv/media/v4l/io.rst +++ b/Documentation/linux_tv/media/v4l/io.rst @@ -9,8 +9,8 @@ The V4L2 API defines several different methods to read from or write to a device. All drivers exchanging data with applications must support at least one of them. -The classic I/O method using the :c:func:`read()` and -:c:func:`write()` function is automatically selected after opening a +The classic I/O method using the :ref:`read() ` and +:ref:`write() ` function is automatically selected after opening a V4L2 device. When the driver does not support this method attempts to read or write will fail at any time. diff --git a/Documentation/linux_tv/media/v4l/media-func-close.rst b/Documentation/linux_tv/media/v4l/media-func-close.rst index 959bfa0cb6a85787a34862793710946b3c9ee694..109b831e40479cfc7d843e4a32e867798628d9e1 100644 --- a/Documentation/linux_tv/media/v4l/media-func-close.rst +++ b/Documentation/linux_tv/media/v4l/media-func-close.rst @@ -38,7 +38,7 @@ are freed. The device configuration remain unchanged. Return Value ============ -:c:func:`close()` returns 0 on success. On error, -1 is returned, and +:ref:`close() ` returns 0 on success. On error, -1 is returned, and ``errno`` is set appropriately. Possible error codes are: EBADF diff --git a/Documentation/linux_tv/media/v4l/media-func-ioctl.rst b/Documentation/linux_tv/media/v4l/media-func-ioctl.rst index d7a3a01771ec0a1641e8dd1832d42b396d2fd052..c56ccb9c9b391f1bc80990b249ba291c2d4850a0 100644 --- a/Documentation/linux_tv/media/v4l/media-func-ioctl.rst +++ b/Documentation/linux_tv/media/v4l/media-func-ioctl.rst @@ -38,7 +38,7 @@ Arguments Description =========== -The :c:func:`ioctl()` function manipulates media device parameters. +The :ref:`ioctl() ` function manipulates media device parameters. The argument ``fd`` must be an open file descriptor. The ioctl ``request`` code specifies the media function to be called. It diff --git a/Documentation/linux_tv/media/v4l/media-func-open.rst b/Documentation/linux_tv/media/v4l/media-func-open.rst index fc731060a726f0688547fb8b561643e7a32dbf85..627860b33ae27dd49ded369ba3a0ecbefdd489a0 100644 --- a/Documentation/linux_tv/media/v4l/media-func-open.rst +++ b/Documentation/linux_tv/media/v4l/media-func-open.rst @@ -35,7 +35,7 @@ Arguments Description =========== -To open a media device applications call :c:func:`open()` with the +To open a media device applications call :ref:`open() ` with the desired device name. The function has no side effects; the device configuration remain unchanged. @@ -47,7 +47,7 @@ EBADF. Return Value ============ -:c:func:`open()` returns the new file descriptor on success. On error, +:ref:`open() ` returns the new file descriptor on success. On error, -1 is returned, and ``errno`` is set appropriately. Possible error codes are: diff --git a/Documentation/linux_tv/media/v4l/mmap.rst b/Documentation/linux_tv/media/v4l/mmap.rst index 5769ed36872ffa3991ad4422f2208280181297f3..1ed17fa3368a59cd0690ad6f1d194476f06f1b8c 100644 --- a/Documentation/linux_tv/media/v4l/mmap.rst +++ b/Documentation/linux_tv/media/v4l/mmap.rst @@ -40,7 +40,7 @@ location of the buffers in device memory can be determined with the :ref:`VIDIOC_QUERYBUF` ioctl. In the single-planar API case, the ``m.offset`` and ``length`` returned in a struct :ref:`v4l2_buffer ` are passed as sixth and second -parameter to the :c:func:`mmap()` function. When using the +parameter to the :ref:`mmap() ` function. When using the multi-planar API, struct :ref:`v4l2_buffer ` contains an array of struct :ref:`v4l2_plane ` structures, each containing its own ``m.offset`` and ``length``. When using the @@ -251,15 +251,15 @@ event it should examine the struct :ref:`v4l2_buffer ` Drivers implementing memory mapping I/O must support the ``VIDIOC_REQBUFS``, ``VIDIOC_QUERYBUF``, ``VIDIOC_QBUF``, ``VIDIOC_DQBUF``, ``VIDIOC_STREAMON`` and ``VIDIOC_STREAMOFF`` ioctl, -the :c:func:`mmap()`, :c:func:`munmap()`, :c:func:`select()` and -:c:func:`poll()` function. [3]_ +the :ref:`mmap() `, :ref:`munmap() `, :ref:`select() ` and +:ref:`poll() ` function. [3]_ [capture example] .. [1] One could use one file descriptor and set the buffer type field accordingly when calling :ref:`VIDIOC_QBUF` etc., - but it makes the :c:func:`select()` function ambiguous. We also + but it makes the :ref:`select() ` function ambiguous. We also like the clean approach of one file descriptor per logical stream. Video overlay for example is also a logical stream, although the CPU is not needed for continuous operation. @@ -272,6 +272,6 @@ the :c:func:`mmap()`, :c:func:`munmap()`, :c:func:`select()` and scatter-gather lists and the like. .. [3] - At the driver level :c:func:`select()` and :c:func:`poll()` are - the same, and :c:func:`select()` is too important to be optional. + At the driver level :ref:`select() ` and :ref:`poll() ` are + the same, and :ref:`select() ` is too important to be optional. The rest should be evident. diff --git a/Documentation/linux_tv/media/v4l/rw.rst b/Documentation/linux_tv/media/v4l/rw.rst index 9dc58651ef022995493a3171280dab6f166d0de8..66ba54648c458a16aaa0c0a3a93d84fe224117c6 100644 --- a/Documentation/linux_tv/media/v4l/rw.rst +++ b/Documentation/linux_tv/media/v4l/rw.rst @@ -6,8 +6,8 @@ Read/Write ********** -Input and output devices support the :c:func:`read()` and -:c:func:`write()` function, respectively, when the +Input and output devices support the :ref:`read() ` and +:ref:`write() ` function, respectively, when the ``V4L2_CAP_READWRITE`` flag in the ``capabilities`` field of struct :ref:`v4l2_capability ` returned by the :ref:`VIDIOC_QUERYCAP` ioctl is set. @@ -43,5 +43,5 @@ driver must also support the :ref:`select() ` and capturing still images. .. [2] - At the driver level :c:func:`select()` and :c:func:`poll()` are - the same, and :c:func:`select()` is too important to be optional. + At the driver level :ref:`select() ` and :ref:`poll() ` are + the same, and :ref:`select() ` is too important to be optional. diff --git a/Documentation/linux_tv/media/v4l/userp.rst b/Documentation/linux_tv/media/v4l/userp.rst index 3f4df1fd984d5d05517323e525e38c2ea7b81eab..f372d39512a81f1cdecca11657ebab11f951c817 100644 --- a/Documentation/linux_tv/media/v4l/userp.rst +++ b/Documentation/linux_tv/media/v4l/userp.rst @@ -94,7 +94,7 @@ outputted buffers. Drivers implementing user pointer I/O must support the ``VIDIOC_REQBUFS``, ``VIDIOC_QBUF``, ``VIDIOC_DQBUF``, ``VIDIOC_STREAMON`` and ``VIDIOC_STREAMOFF`` ioctl, the -:c:func:`select()` and :c:func:`poll()` function. [2]_ +:ref:`select() ` and :ref:`poll() ` function. [2]_ .. [1] We expect that frequently used buffers are typically not swapped out. @@ -109,6 +109,6 @@ Drivers implementing user pointer I/O must support the because an application may share them with other processes. .. [2] - At the driver level :c:func:`select()` and :c:func:`poll()` are - the same, and :c:func:`select()` is too important to be optional. + At the driver level :ref:`select() ` and :ref:`poll() ` are + the same, and :ref:`select() ` is too important to be optional. The rest should be evident. diff --git a/Documentation/linux_tv/media/v4l/vidioc-decoder-cmd.rst b/Documentation/linux_tv/media/v4l/vidioc-decoder-cmd.rst index 5f7be4ee8a51e99acca8886c793766c617c5c879..f75698d7caca586035759cbcf080792830addecd 100644 --- a/Documentation/linux_tv/media/v4l/vidioc-decoder-cmd.rst +++ b/Documentation/linux_tv/media/v4l/vidioc-decoder-cmd.rst @@ -43,11 +43,11 @@ this structure. The ``cmd`` field must contain the command code. Some commands use the ``flags`` field for additional information. -A :c:func:`write()`() or :ref:`VIDIOC_STREAMON` +A :ref:`write() ` or :ref:`VIDIOC_STREAMON` call sends an implicit START command to the decoder if it has not been started yet. -A :c:func:`close()`() or :ref:`VIDIOC_STREAMOFF ` +A :ref:`close() ` or :ref:`VIDIOC_STREAMOFF ` call of a streaming file descriptor sends an implicit immediate STOP command to the decoder, and all buffered data is discarded. diff --git a/Documentation/linux_tv/media/v4l/vidioc-encoder-cmd.rst b/Documentation/linux_tv/media/v4l/vidioc-encoder-cmd.rst index cd7cc4bfd7561385b3d42c6c0a929521ce572470..a5056f829e15c4545a0ca0061a24ebceddcd4e81 100644 --- a/Documentation/linux_tv/media/v4l/vidioc-encoder-cmd.rst +++ b/Documentation/linux_tv/media/v4l/vidioc-encoder-cmd.rst @@ -48,14 +48,14 @@ currently only used by the STOP command and contains one bit: If the until the end of the current *Group Of Pictures*, otherwise it will stop immediately. -A :c:func:`read()`() or :ref:`VIDIOC_STREAMON` +A :ref:`read() ` or :ref:`VIDIOC_STREAMON ` call sends an implicit START command to the encoder if it has not been -started yet. After a STOP command, :c:func:`read()`() calls will read +started yet. After a STOP command, :ref:`read() ` calls will read the remaining data buffered by the driver. When the buffer is empty, -:c:func:`read()`() will return zero and the next :c:func:`read()`() +:ref:`read() ` will return zero and the next :ref:`read() ` call will restart the encoder. -A :c:func:`close()`() or :ref:`VIDIOC_STREAMOFF ` +A :ref:`close() ` or :ref:`VIDIOC_STREAMOFF ` call of a streaming file descriptor sends an implicit immediate STOP to the encoder, and all buffered data is discarded. diff --git a/Documentation/linux_tv/media/v4l/vidioc-g-parm.rst b/Documentation/linux_tv/media/v4l/vidioc-g-parm.rst index 0f96b95ebc0ecb66d19f93fd41d6d9e0aa938bb8..480d2923c98257ec62f33e048fbe78ee00b9283d 100644 --- a/Documentation/linux_tv/media/v4l/vidioc-g-parm.rst +++ b/Documentation/linux_tv/media/v4l/vidioc-g-parm.rst @@ -35,8 +35,8 @@ Description The current video standard determines a nominal number of frames per second. If less than this number of frames is to be captured or output, applications can request frame skipping or duplicating on the driver -side. This is especially useful when using the :c:func:`read()` or -:c:func:`write()`, which are not augmented by timestamps or sequence +side. This is especially useful when using the :ref:`read() ` or +:ref:`write() `, which are not augmented by timestamps or sequence counters, and to avoid unnecessary data copying. Further these ioctls can be used to determine the number of buffers used @@ -260,7 +260,7 @@ union holding separate parameters for input and output devices. - ``writebuffers`` - Applications set this field to the desired number of buffers used - internally by the driver in :c:func:`write()` mode. Drivers + internally by the driver in :ref:`write() ` mode. Drivers return the actual number of buffers. When an application requests zero buffers, drivers should just return the current setting rather than the minimum or an error code. For details see @@ -337,7 +337,7 @@ union holding separate parameters for input and output devices. - Moving objects in the image might have excessive motion blur. - - Capture might only work through the :c:func:`read()` call. + - Capture might only work through the :ref:`read() ` call.