Hi Boris, On Fri, Dec 13, 2019 at 01:54:08PM +0100, Boris Brezillon wrote: > vb2_request_get_buf() returns the N-th buffer attached to a media > request. > > Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx> > --- > Changes in v3: > * None > > Changes in v2: > * Adjust the kernel doc as suggested by Hans > --- > .../media/common/videobuf2/videobuf2-core.c | 23 +++++++++++++++++++ > include/media/videobuf2-core.h | 11 +++++++++ > 2 files changed, 34 insertions(+) > > diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c > index 4489744fbbd9..c4c7980dcb0d 100644 > --- a/drivers/media/common/videobuf2/videobuf2-core.c > +++ b/drivers/media/common/videobuf2/videobuf2-core.c > @@ -1416,6 +1416,29 @@ unsigned int vb2_request_buffer_cnt(struct media_request *req) > } > EXPORT_SYMBOL_GPL(vb2_request_buffer_cnt); > > +struct vb2_buffer *vb2_request_get_buf(struct media_request *req, > + unsigned int n) > +{ > + struct media_request_object *obj; > + struct vb2_buffer *buf = NULL; > + unsigned int nbufs = 0; > + unsigned long flags; > + > + spin_lock_irqsave(&req->lock, flags); > + list_for_each_entry(obj, &req->objects, list) { > + if (!vb2_request_object_is_buffer(obj) || > + nbufs++ < n) > + continue; > + > + buf = container_of(obj, struct vb2_buffer, req_obj); > + break; > + } > + spin_unlock_irqrestore(&req->lock, flags); > + > + return buf; > +} > +EXPORT_SYMBOL_GPL(vb2_request_get_buf); > + > int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb) > { > struct vb2_buffer *vb; > diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h > index a2b2208b02da..6206e25df764 100644 > --- a/include/media/videobuf2-core.h > +++ b/include/media/videobuf2-core.h > @@ -1225,4 +1225,15 @@ bool vb2_request_object_is_buffer(struct media_request_object *obj); > */ > unsigned int vb2_request_buffer_cnt(struct media_request *req); > > +/** > + * vb2_request_get_buf() - return the buffer at index @idx > + * > + * @req: the request. > + * @n: search for the Nth buffer in the req object list It's not very clear to me what "n" is here. Wouldn't it be better to pass the queue pointer instead, to get a buffer for a given queue ? > + * > + * Return a vb2 buffer or NULL if there's no buffer at the specified position > + */ > +struct vb2_buffer *vb2_request_get_buf(struct media_request *req, > + unsigned int n); > + > #endif /* _MEDIA_VIDEOBUF2_CORE_H */ -- Regards, Laurent Pinchart