summaryrefslogtreecommitdiffstats
path: root/Documentation/userspace-api/media/mediactl/media-request-ioc-reinit.rst
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/userspace-api/media/mediactl/media-request-ioc-reinit.rst')
-rw-r--r--Documentation/userspace-api/media/mediactl/media-request-ioc-reinit.rst51
1 files changed, 51 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/mediactl/media-request-ioc-reinit.rst b/Documentation/userspace-api/media/mediactl/media-request-ioc-reinit.rst
new file mode 100644
index 0000000000..57567b87b9
--- /dev/null
+++ b/Documentation/userspace-api/media/mediactl/media-request-ioc-reinit.rst
@@ -0,0 +1,51 @@
+.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later
+.. c:namespace:: MC
+
+.. _media_request_ioc_reinit:
+
+******************************
+ioctl MEDIA_REQUEST_IOC_REINIT
+******************************
+
+Name
+====
+
+MEDIA_REQUEST_IOC_REINIT - Re-initialize a request
+
+Synopsis
+========
+
+.. c:macro:: MEDIA_REQUEST_IOC_REINIT
+
+``int ioctl(int request_fd, MEDIA_REQUEST_IOC_REINIT)``
+
+Arguments
+=========
+
+``request_fd``
+ File descriptor returned by :ref:`MEDIA_IOC_REQUEST_ALLOC`.
+
+Description
+===========
+
+If the media device supports :ref:`requests <media-request-api>`, then
+this request ioctl can be used to re-initialize a previously allocated
+request.
+
+Re-initializing a request will clear any existing data from the request.
+This avoids having to :c:func:`close()` a completed
+request and allocate a new request. Instead the completed request can just
+be re-initialized and it is ready to be used again.
+
+A request can only be re-initialized if it either has not been queued
+yet, or if it was queued and completed. Otherwise it will set ``errno``
+to ``EBUSY``. No other error codes can be returned.
+
+Return Value
+============
+
+On success 0 is returned, on error -1 and the ``errno`` variable is set
+appropriately.
+
+EBUSY
+ The request is queued but not yet completed.