Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 74 insertions, 0 deletions

diff --git a/Documentation/userspace-api/media/cec/cec-func-poll.rst b/Documentation/userspace-api/media/cec/cec-func-poll.rst
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+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+.. c:namespace:: CEC
+
+.. _cec-func-poll:
+
+**********
+cec poll()
+**********
+
+Name
+====
+
+cec-poll - Wait for some event on a file descriptor
+
+Synopsis
+========
+
+.. code-block:: c
+
+    #include <sys/poll.h>
+
+.. c:function:: int poll( struct pollfd *ufds, unsigned int nfds, int timeout )
+
+Arguments
+=========
+
+``ufds``
+   List of FD events to be watched
+
+``nfds``
+   Number of FD events at the \*ufds array
+
+``timeout``
+   Timeout to wait for events
+
+Description
+===========
+
+With the :c:func:`poll()` function applications can wait for CEC
+events.
+
+On success :c:func:`poll()` returns the number of file descriptors
+that have been selected (that is, file descriptors for which the
+``revents`` field of the respective struct :c:type:`pollfd`
+is non-zero). CEC devices set the ``POLLIN`` and ``POLLRDNORM`` flags in
+the ``revents`` field if there are messages in the receive queue. If the
+transmit queue has room for new messages, the ``POLLOUT`` and
+``POLLWRNORM`` flags are set. If there are events in the event queue,
+then the ``POLLPRI`` flag is set. When the function times out it returns
+a value of zero, on failure it returns -1 and the ``errno`` variable is
+set appropriately.
+
+For more details see the :c:func:`poll()` manual page.
+
+Return Value
+============
+
+On success, :c:func:`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:
+
+``EBADF``
+    One or more of the ``ufds`` members specify an invalid file
+    descriptor.
+
+``EFAULT``
+    ``ufds`` references an inaccessible memory area.
+
+``EINTR``
+    The call was interrupted by a signal.
+
+``EINVAL``
+    The ``nfds`` value exceeds the ``RLIMIT_NOFILE`` value. Use
+    ``getrlimit()`` to obtain this value.