From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- .../DocBook/media/v4l/vidioc-prepare-buf.xml | 94 ++++++++++++++++++++++ 1 file changed, 94 insertions(+) create mode 100644 Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml (limited to 'Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml') diff --git a/Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml b/Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml new file mode 100644 index 000000000..fa7ad7e33 --- /dev/null +++ b/Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml @@ -0,0 +1,94 @@ + + + ioctl VIDIOC_PREPARE_BUF + &manvol; + + + + VIDIOC_PREPARE_BUF + Prepare a buffer for I/O + + + + + + int ioctl + int fd + int request + struct v4l2_buffer *argp + + + + + + Arguments + + + + fd + + &fd; + + + + request + + VIDIOC_PREPARE_BUF + + + + argp + + + + + + + + + Description + + + Experimental + This is an experimental + interface and may change in the future. + + + Applications can optionally call the +VIDIOC_PREPARE_BUF ioctl to pass ownership of the buffer +to the driver before actually enqueuing it, using the +VIDIOC_QBUF ioctl, and to prepare it for future I/O. +Such preparations may include cache invalidation or cleaning. Performing them +in advance saves time during the actual I/O. In case such cache operations are +not required, the application can use one of +V4L2_BUF_FLAG_NO_CACHE_INVALIDATE and +V4L2_BUF_FLAG_NO_CACHE_CLEAN flags to skip the respective +step. + + The v4l2_buffer structure is +specified in . + + + + &return-value; + + + + EBUSY + + File I/O is in progress. + + + + EINVAL + + The buffer type is not +supported, or the index is out of bounds, +or no buffers have been allocated yet, or the +userptr or +length are invalid. + + + + + -- cgit v1.2.3-54-g00ecf