On 06/16/17 09:39, Gustavo Padovan wrote:
> From: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxx>
>
> In order to support explicit synchronization we need to divide
> vb2_core_qbuf() in two parts, one to be executed before the fence
> signals and another one to do the actual queueing of the buffer.
>
> Signed-off-by: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/videobuf2-core.c | 51 ++++++++++++++++++--------------
> 1 file changed, 29 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
> index 3107e21..ea83126 100644
> --- a/drivers/media/v4l2-core/videobuf2-core.c
> +++ b/drivers/media/v4l2-core/videobuf2-core.c
> @@ -1367,6 +1367,34 @@ static int vb2_start_streaming(struct vb2_queue *q)
> return ret;
> }
>
> +static int __vb2_core_qbuf(struct vb2_buffer *vb, struct vb2_queue *q)
> +{
> + int ret;
> +
> + /*
> + * If already streaming, give the buffer to driver for processing.
> + * If not, the buffer will be given to driver on next streamon.
> + */
> + if (q->start_streaming_called)
> + __enqueue_in_driver(vb);
> +
> + /*
> + * If streamon has been called, and we haven't yet called
> + * start_streaming() since not enough buffers were queued, and
> + * we now have reached the minimum number of queued buffers,
> + * then we can finally call start_streaming().
> + */
> + if (q->streaming && !q->start_streaming_called &&
> + q->queued_count >= q->min_buffers_needed) {
> + ret = vb2_start_streaming(q);
> + if (ret)
> + return ret;
> + }
> +
> + dprintk(1, "qbuf of buffer %d succeeded\n", vb->index);
> + return 0;
> +}
> +
> int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
> {
> struct vb2_buffer *vb;
> @@ -1404,32 +1432,11 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
>
> trace_vb2_qbuf(q, vb);
>
> - /*
> - * If already streaming, give the buffer to driver for processing.
> - * If not, the buffer will be given to driver on next streamon.
> - */
> - if (q->start_streaming_called)
> - __enqueue_in_driver(vb);
> -
> /* Fill buffer information for the userspace */
> if (pb)
> call_void_bufop(q, fill_user_buffer, vb, pb);
This should be called *after* the __vb2_core_qbuf call. That call changes
vb->state which is used by buffer to fill in v4l2_buffer. So the order
should be swapped here to ensure we return the latest state of the buffer.
>
> - /*
> - * If streamon has been called, and we haven't yet called
> - * start_streaming() since not enough buffers were queued, and
> - * we now have reached the minimum number of queued buffers,
> - * then we can finally call start_streaming().
> - */
> - if (q->streaming && !q->start_streaming_called &&
> - q->queued_count >= q->min_buffers_needed) {
> - ret = vb2_start_streaming(q);
> - if (ret)
> - return ret;
> - }
> -
> - dprintk(1, "qbuf of buffer %d succeeded\n", vb->index);
> - return 0;
> + return __vb2_core_qbuf(vb, q);
> }
> EXPORT_SYMBOL_GPL(vb2_core_qbuf);
>
>
Regards,
Hans
