[libcamera-devel] [PATCH 12/13] libcamera: pipeline: simple: Don't disable links carrying other streams

[Jacopo Mondi]

Hi Laurent

On Mon, Aug 01, 2022 at 11:59:33PM +0300, Laurent Pinchart wrote:
> Hi Jacopo,
>
> On Mon, Aug 01, 2022 at 06:25:23PM +0200, Jacopo Mondi wrote:
> > On Mon, Aug 01, 2022 at 03:05:42AM +0300, Laurent Pinchart via libcamera-devel wrote:
> > > From: Phi-Bang Nguyen <pnguyen at baylibre.com>
> > >
> > > If a subdev supports the internal routing API, pads unrelated to the
> > > pipeline for a given camera sensor may carry streams for other cameras.
> > > The link setup logic is updated to take this into account, by avoiding
> > > disabling links to unrelated pads.
> > >
> > > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > > ---
> > >  src/libcamera/pipeline/simple/simple.cpp | 28 +++++++++++++++++++++---
> > >  1 file changed, 25 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp
> > > index 2a8811183907..c80e462bc449 100644
> > > --- a/src/libcamera/pipeline/simple/simple.cpp
> > > +++ b/src/libcamera/pipeline/simple/simple.cpp
> > > @@ -221,6 +221,11 @@ public:
> > >  	struct Entity {
> > >  		/* The media entity, always valid. */
> > >  		MediaEntity *entity;
> > > +		/*
> > > +		 * Whether or not the entity is a subdev that supports the
> > > +		 * routing API.
> > > +		 */
> > > +		bool supportsRouting;
> > >  		/*
> > >  		 * The local sink pad connected to the upstream entity, null for
> > >  		 * the camera sensor at the beginning of the pipeline.
> > > @@ -404,9 +409,13 @@ SimpleCameraData::SimpleCameraData(SimplePipelineHandler *pipe,
> > >  		 */
> > >
> > >  		std::vector<const MediaPad *> pads;
> > > +		bool supportsRouting = false;
> > >
> > > -		if (sinkPad)
> > > +		if (sinkPad) {
> > >  			pads = routedSourcePads(sinkPad);
> > > +			if (!pads.empty())
> > > +				supportsRouting = true;
> > > +		}
> > >
> > >  		if (pads.empty()) {
> > >  			for (const MediaPad *pad : entity->pads()) {
> > > @@ -421,7 +430,9 @@ SimpleCameraData::SimpleCameraData(SimplePipelineHandler *pipe,
> > >  				MediaEntity *next = link->sink()->entity();
> > >  				if (visited.find(next) == visited.end()) {
> > >  					queue.push({ next, link->sink() });
> > > -					parents.insert({ next, { entity, sinkPad, pad, link } });
> > > +
> > > +					Entity e{ entity, supportsRouting, sinkPad, pad, link };
> > > +					parents.insert({ next, e });
> > >  				}
> > >  			}
> > >  		}
> > > @@ -435,7 +446,7 @@ SimpleCameraData::SimpleCameraData(SimplePipelineHandler *pipe,
> > >  	 * to the sensor. Store all the entities in the pipeline, from the
> > >  	 * camera sensor to the video node, in entities_.
> > >  	 */
> > > -	entities_.push_front({ entity, sinkPad, nullptr, nullptr });
> > > +	entities_.push_front({ entity, false, sinkPad, nullptr, nullptr });
> > >
> > >  	for (auto it = parents.find(entity); it != parents.end();
> > >  	     it = parents.find(entity)) {
> > > @@ -617,6 +628,17 @@ int SimpleCameraData::setupLinks()
> >
> > I would also update the comment at function begin that reports
> >
> > 	/*
> > 	 * Configure all links along the pipeline. Some entities may not allow
> > 	 * multiple sink links to be enabled together, even on different sink
> > 	 * pads. We must thus start by disabling all sink links (but the one we
> > 	 * want to enable) before enabling the pipeline link.
> > 	 */
> >
> > To mention that this doesn't apply to routed subdevs
>
> I had a look but it would really duplicate the comment below. As it
> describes the internal implementation and not a public API, and the two
> comments are 9 lines of code apart, would you mind if I left it as-is ?
>

fine

> > >  		}
> > >
> > >  		for (MediaPad *pad : e.entity->pads()) {
> > > +			/*
> > > +			 * If the entity supports the V4L2 internal routing API,
> > > +			 * assume that it may carry multiple independent streams
> > > +			 * concurrently, and only disable links on the sink and
> > > +			 * source pads used by the pipeline.
> > > +			 */
> > > +			if (e.supportsRouting) {
> > > +				if (pad != e.sink && pad != e.source)
> >
> > Or
> >                         if (e.supportsRouting &&
> >                             (pad != e.sink && pad != e.source))
>
> I'll drop the inner parentheses too.

Better thanks

>
> > > +					continue;
> > > +			}
> > > +
> > >  			for (MediaLink *link : pad->links()) {
> > >  				if (link == sinkLink)
> > >  					continue;
>
> --
> Regards,
>
> Laurent Pinchart