/**
* vb2_streamoff - stop streaming
* @q: videobuf2 queue
* @type: type argument passed from userspace to vidioc_streamoff handler
*
* Should be called from vidioc_streamoff handler of a driver.
* This function:
* 1) verifies current state,
* 2) stop streaming and dequeues any queued buffers, including those previously
* passed to the driver (after waiting for the driver to finish).
*
* This call can be used for pausing playback.
* The return values from this function are intended to be directly returned
* from vidioc_streamoff handler in the driver
*/
int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
{
if (q->fileio) {
dprintk(1, "streamoff: file io in progress\n");
return -EBUSY;
}
if (type != q->type) {
dprintk(1, "streamoff: invalid stream type\n");
return -EINVAL;
}
if (!q->streaming) {
dprintk(1, "streamoff: not streaming\n");
return -EINVAL;
}
/*
* Cancel will pause streaming and remove all buffers from the driver
* and videobuf, effectively returning control over them to userspace.
*/
__vb2_queue_cancel(q);
dprintk(3, "Streamoff successful\n");
return 0;
}
int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
{
struct vb2_buffer *vb;
int ret;
if (q->fileio) {
dprintk(1, "streamon: file io in progress\n");
return -EBUSY;
}
if (type != q->type) {
dprintk(1, "streamon: invalid stream type\n");
return -EINVAL;
}
if (q->streaming) {
dprintk(1, "streamon: already streaming\n");
return -EBUSY;
}
list_for_each_entry(vb, &q->queued_list, queued_entry)
__enqueue_in_driver(vb);
ret = call_qop(q, start_streaming, q, atomic_read(&q->queued_count));
if (ret) {
dprintk(1, "streamon: driver refused to start streaming\n");
__vb2_queue_cancel(q);
return ret;
}
q->streaming = 1;
dprintk(3, "Streamon successful\n");
return 0;
}
int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
{
if (q->fileio) {
dprintk(1, "streamoff: file io in progress\n");
return -EBUSY;
}
if (type != q->type) {
dprintk(1, "streamoff: invalid stream type\n");
return -EINVAL;
}
if (!q->streaming) {
dprintk(1, "streamoff: not streaming\n");
return -EINVAL;
}
__vb2_queue_cancel(q);
dprintk(3, "Streamoff successful\n");
return 0;
}
/**
* vb2_queue_release() - stop streaming, release the queue and free memory
* @q: videobuf2 queue
*
* This function stops streaming and performs necessary clean ups, including
* freeing video buffer memory. The driver is responsible for freeing
* the vb2_queue structure itself.
*/
void vb2_queue_release(struct vb2_queue *q)
{
__vb2_cleanup_fileio(q);
__vb2_queue_cancel(q);
__vb2_queue_free(q);
}