diff options
Diffstat (limited to 'Documentation/video4linux/v4l2-framework.txt')
| -rw-r--r-- | Documentation/video4linux/v4l2-framework.txt | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt index 7d09114af00..3b15608ee07 100644 --- a/Documentation/video4linux/v4l2-framework.txt +++ b/Documentation/video4linux/v4l2-framework.txt @@ -577,6 +577,10 @@ You should also set these fields: (cx8802). Since the v4l2_device cannot be associated with a particular PCI device it is setup without a parent device. But when the struct video_device is setup you do know which parent PCI device to use. +- flags: optional. Set to V4L2_FL_USE_FH_PRIO if you want to let the framework + handle the VIDIOC_G/S_PRIORITY ioctls. This requires that you use struct + v4l2_fh. Eventually this flag will disappear once all drivers use the core + priority handling. But for now it has to be set explicitly. If you use v4l2_ioctl_ops, then you should set .unlocked_ioctl to video_ioctl2 in your v4l2_file_operations struct. @@ -775,7 +779,8 @@ struct v4l2_fh struct v4l2_fh provides a way to easily keep file handle specific data that is used by the V4L2 framework. New drivers must use struct v4l2_fh -since it is also used to implement priority handling (VIDIOC_G/S_PRIORITY). +since it is also used to implement priority handling (VIDIOC_G/S_PRIORITY) +if the video_device flag V4L2_FL_USE_FH_PRIO is also set. The users of v4l2_fh (in the V4L2 framework, not the driver) know whether a driver uses v4l2_fh as its file->private_data pointer by |