On Tue, 5 Apr 2011, Laurent Pinchart wrote:
> Hi Guennadi,
>
> On Friday 01 April 2011 16:06:42 Guennadi Liakhovetski wrote:
> > This patch extends the videobuf2 framework with new helper functions and
> > modifies existing ones to support multi-size video-buffers.
>
> [snip]
>
> > diff --git a/include/media/videobuf2-core.h
> > b/include/media/videobuf2-core.h index f87472a..88076fc 100644
> > --- a/include/media/videobuf2-core.h
> > +++ b/include/media/videobuf2-core.h
> > @@ -177,6 +177,10 @@ struct vb2_buffer {
> > * plane should be set in the sizes[] array and optional
> > * per-plane allocator specific context in alloc_ctxs[]
> > * array
> > + * @queue_add: like above, but called from VIDIOC_CREATE_BUFS, but if
> > + * there are already buffers on the queue, it won't replace
> > + * them, but add new ones, possibly with a different format
> > + * and plane sizes
>
> I don't think drivers will need to perform different operations in queue_setup
> and queue_add. You could merge the two operations.
In principle yes. That's also what I ended up doing internally in the
sh-mobile driver. Would have to change existing drivers then...
> > * @wait_prepare: release any locks taken while calling vb2 functions;
> > * it is called before an ioctl needs to wait for a new
> > * buffer to arrive; required to avoid a deadlock in
> > @@ -194,6 +198,8 @@ struct vb2_buffer {
> > * each hardware operation in this callback;
> > * if an error is returned, the buffer will not be queued
> > * in driver; optional
> > + * @buf_submit: called primarily to invalidate buffer caches for faster
> > + * consequent queuing; optional
>
> What's the difference between buf_submit and buf_prepare ?
My confusion;) Clarified this with Hans too already.
> > * @buf_finish: called before every dequeue of the buffer back to
> > * userspace; drivers may perform any operations required
> > * before userspace accesses the buffer; optional
>
> --
> Regards,
>
> Laurent Pinchart
Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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