On Tue, Jan 22, 2019 at 05:38:48PM +0200, Laurent Pinchart wrote:
> Hi Sakari,
>
> On Tue, Jan 22, 2019 at 05:36:55PM +0200, Sakari Ailus wrote:
> > On Wed, Jan 16, 2019 at 01:24:05AM +0200, Laurent Pinchart wrote:
> > > On Fri, Nov 02, 2018 at 12:31:26AM +0100, Niklas Söderlund wrote:
> > >> From: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> > >>
> > >> Add a helper macro for iterating over pads that are connected through
> > >> enabled routes. This can be used to find all the connected pads within an
> > >> entity, for instance starting from the pad which has been obtained during
> > >> the graph walk.
> > >>
> > >> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> > >> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
> > >> ---
> > >> include/media/media-entity.h | 27 +++++++++++++++++++++++++++
> > >> 1 file changed, 27 insertions(+)
> > >>
> > >> diff --git a/include/media/media-entity.h b/include/media/media-entity.h
> > >> index 9540d2af80f19805..4bb1b568e1ac4795 100644
> > >> --- a/include/media/media-entity.h
> > >> +++ b/include/media/media-entity.h
> > >> @@ -936,6 +936,33 @@ __must_check int media_graph_walk_init(
> > >> bool media_entity_has_route(struct media_entity *entity, unsigned int pad0,
> > >> unsigned int pad1);
> > >>
> > >> +static inline struct media_pad *__media_entity_for_routed_pads_next(
> > >> + struct media_pad *start, struct media_pad *iter)
> > >> +{
> > >> + struct media_entity *entity = start->entity;
> > >> +
> > >> + while (iter < &entity->pads[entity->num_pads] &&
> > >> + !media_entity_has_route(entity, start->index, iter->index))
> > >> + iter++;
> > >> +
> > >> + return iter;
> > >
> > > Returning a pointer past the end of the array is asking for trouble. I
> > > think we should return NULL in that case, and adapt the check in
> > > media_entity_for_routed_pads() accordingly.
> >
> > Well, that pointer never gets used, in a similar manner than simply looping
> > over an array. I wouldn't change that --- this function is also integrally
> > a part of media_entity_for_each_routed_pad() implementation below.
>
> I know it doesn't get used, but it's still asking for trouble, it will
> be easy to use it by mistake. Returning NULL would be clearer.
Hmph. Well, that's a fair point, too... The caller must be also changed to
cope with NULL then. It'd be nice to see the end result of that for it's
already fairly complex.
>
> > >> +}
> > >> +
> > >> +/**
> > >> + * media_entity_for_routed_pads - Iterate over entity pads connected by routes
> > >> + *
> > >> + * @start: The stating pad
> > >
> > > s/stating/starting/
> > >
> > >> + * @iter: The iterator pad
> > >> + *
> > >> + * Iterate over all pads connected through routes from a given pad
> > >> + * within an entity. The iteration will include the starting pad itself.
> > >> + */
> > >> +#define media_entity_for_routed_pads(start, iter) \
> > >
> > > Maybe media_entity_for_each_routed_pad() ? Or just
> >
> > I'd prefer this one: we have media_entity_ prefix for pretty much
> > everything that handles entities.
>
> It's a bit long, but OK.
>
> > > for_each_entity_routed_pad() ?
> > >
> > >> + for (iter = __media_entity_for_routed_pads_next( \
> > >
> > > And how about __media_entity_next_routed_pad() ?
> >
> > Yes.
> >
> > >
> > >> + start, (start)->entity->pads); \
> > >> + iter < &(start)->entity->pads[(start)->entity->num_pads]; \
> > >> + iter = __media_entity_for_routed_pads_next(start, iter + 1))
> > >> +
> > >> /**
> > >> * media_graph_walk_cleanup - Release resources used by graph walk.
> > >> *
>
> --
> Regards,
>
> Laurent Pinchart
--
Sakari Ailus
sakari.ailus@xxxxxxxxxxxxxxx
