diff options
| author | Hans Verkuil <hverkuil@xs4all.nl> | 2014-07-23 08:17:06 +0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <m.chehab@samsung.com> | 2014-07-26 00:19:35 +0200 |
| commit | ccf58cb4eac050ebe777cfcb209bc53d58f5fd79 (patch) | |
| tree | 385a7bc450993342ccfb74d017c300575f87bb7a /include/media | |
| parent | [media] v4l2-ctrls: add support for setting string controls (diff) | |
| download | linux-ccf58cb4eac050ebe777cfcb209bc53d58f5fd79.tar.xz linux-ccf58cb4eac050ebe777cfcb209bc53d58f5fd79.zip | |
[media] vb2: fix videobuf2-core.h comments
A lot of work was done in vb2 to regulate how drivers and the vb2 core handle
buffer ownership, but inexplicably the videobuf2-core.h comments were never
updated. Do so now. The same was true for the replacement of the -ENOBUFS
mechanism by the min_buffers_needed field.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Diffstat (limited to 'include/media')
| -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; |