diff options
| -rw-r--r-- | include/media/videobuf2-core.h | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index 1a262aeb1741..fc910a622451 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -294,15 +294,19 @@ struct vb2_buffer { * of already queued buffers in count parameter; driver * can return an error if hardware fails, in that case all * buffers that have been already given by the @buf_queue - * callback are invalidated. - * If there were not enough queued buffers to start - * streaming, then this callback returns -ENOBUFS, and the - * vb2 core will retry calling @start_streaming when a new - * buffer is queued. + * callback are to be returned by the driver by calling + * @vb2_buffer_done(VB2_BUF_STATE_DEQUEUED). + * If you need a minimum number of buffers before you can + * start streaming, then set @min_buffers_needed in the + * vb2_queue structure. If that is non-zero then + * start_streaming won't be called until at least that + * many buffers have been queued up by userspace. * @stop_streaming: called when 'streaming' state must be disabled; driver * should stop any DMA transactions or wait until they * finish and give back all buffers it got from buf_queue() - * callback; may use vb2_wait_for_all_buffers() function + * callback by calling @vb2_buffer_done() with either + * VB2_BUF_STATE_DONE or VB2_BUF_STATE_ERROR; may use + * vb2_wait_for_all_buffers() function * @buf_queue: passes buffer vb to the driver; driver may start * hardware operation on this buffer; driver should give * the buffer back by calling vb2_buffer_done() function; |