diff options
| -rw-r--r-- | include/media/videobuf2-core.h | 32 |
1 files changed, 17 insertions, 15 deletions
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index 6ef2d01197da..70ace7cc6087 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -270,22 +270,24 @@ struct vb2_buffer { * queue setup from completing successfully; optional. * @buf_prepare: called every time the buffer is queued from userspace * and from the VIDIOC_PREPARE_BUF ioctl; drivers may - * perform any initialization required before each hardware - * operation in this callback; drivers that support - * VIDIOC_CREATE_BUFS must also validate the buffer size; - * if an error is returned, the buffer will not be queued - * in driver; optional. + * perform any initialization required before each + * hardware operation in this callback; drivers can + * access/modify the buffer here as it is still synced for + * the CPU; drivers that support VIDIOC_CREATE_BUFS must + * also validate the buffer size; if an error is returned, + * the buffer will not be queued in driver; optional. * @buf_finish: called before every dequeue of the buffer back to - * userspace; drivers may perform any operations required - * before userspace accesses the buffer; optional. The - * buffer state can be one of the following: DONE and - * ERROR occur while streaming is in progress, and the - * PREPARED state occurs when the queue has been canceled - * and all pending buffers are being returned to their - * default DEQUEUED state. Typically you only have to do - * something if the state is VB2_BUF_STATE_DONE, since in - * all other cases the buffer contents will be ignored - * anyway. + * userspace; the buffer is synced for the CPU, so drivers + * can access/modify the buffer contents; drivers may + * perform any operations required before userspace + * accesses the buffer; optional. The buffer state can be + * one of the following: DONE and ERROR occur while + * streaming is in progress, and the PREPARED state occurs + * when the queue has been canceled and all pending + * buffers are being returned to their default DEQUEUED + * state. Typically you only have to do something if the + * state is VB2_BUF_STATE_DONE, since in all other cases + * the buffer contents will be ignored anyway. * @buf_cleanup: called once before the buffer is freed; drivers may * perform any additional cleanup; optional. * @start_streaming: called once to enter 'streaming' state; the driver may |