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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/userspace-api/media/mediactl/media-ioc-setup-link.rst | |
parent | Initial commit. (diff) | |
download | linux-430c2fc249ea5c0536abd21c23382884005c9093.tar.xz linux-430c2fc249ea5c0536abd21c23382884005c9093.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/userspace-api/media/mediactl/media-ioc-setup-link.rst')
-rw-r--r-- | Documentation/userspace-api/media/mediactl/media-ioc-setup-link.rst | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/mediactl/media-ioc-setup-link.rst b/Documentation/userspace-api/media/mediactl/media-ioc-setup-link.rst new file mode 100644 index 000000000..23208300c --- /dev/null +++ b/Documentation/userspace-api/media/mediactl/media-ioc-setup-link.rst @@ -0,0 +1,65 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: MC + +.. _media_ioc_setup_link: + +************************** +ioctl MEDIA_IOC_SETUP_LINK +************************** + +Name +==== + +MEDIA_IOC_SETUP_LINK - Modify the properties of a link + +Synopsis +======== + +.. c:macro:: MEDIA_IOC_SETUP_LINK + +``int ioctl(int fd, MEDIA_IOC_SETUP_LINK, struct media_link_desc *argp)`` + +Arguments +========= + +``fd`` + File descriptor returned by :c:func:`open()`. + +``argp`` + Pointer to struct :c:type:`media_link_desc`. + +Description +=========== + +To change link properties applications fill a struct +:c:type:`media_link_desc` with link identification +information (source and sink pad) and the new requested link flags. They +then call the MEDIA_IOC_SETUP_LINK ioctl with a pointer to that +structure. + +The only configurable property is the ``ENABLED`` link flag to +enable/disable a link. Links marked with the ``IMMUTABLE`` link flag can +not be enabled or disabled. + +Link configuration has no side effect on other links. If an enabled link +at the sink pad prevents the link from being enabled, the driver returns +with an ``EBUSY`` error code. + +Only links marked with the ``DYNAMIC`` link flag can be enabled/disabled +while streaming media data. Attempting to enable or disable a streaming +non-dynamic link will return an ``EBUSY`` error code. + +If the specified link can't be found the driver returns with an ``EINVAL`` +error code. + +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 struct :c:type:`media_link_desc` references a + non-existing link, or the link is immutable and an attempt to modify + its configuration was made. |