[libcamera-devel] [PATCH v2 1/4] cam: fix order camera is operated on

[Niklas Söderlund]

Hi Laurent,

Thanks for your feedback.

On 2019-02-28 19:14:37 +0200, Laurent Pinchart wrote:
> Hi Niklas,
> 
> Thank you for the patch.
> 
> On Thu, Feb 28, 2019 at 03:16:23AM +0100, Niklas Söderlund wrote:
> > Upcoming enforcing of order the camera shall be operate on is not
> > compatible with the cam utility. Requests shall be queued after the
> > camera is started, not before.
> 
> My comment on v1 hasn't been addressed. Could you at least add a \todo
> in the state machine patch to remind us to document camera start timings
> ? I'm still not sure that preventing requests from being queued before
> calling start() will not come back to bite us later, but for now I can't
> think of a good alternative, so

I will add a \todo to 3/4, sorry for missing this. How about?

 * \todo Add documentation for camera star timings. What exactly do the
 * camera expect the pipeline handler to do when start() is called.

I agree we might need to relax the criteria for when requests can be 
queued in the future. For now I think this is the right thing to do and 
we can change it later if we discover a need for it.

> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> 
> (with the added todo in 3/4)
> 
> > Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> > ---
> >  src/cam/main.cpp | 18 +++++++++++-------
> >  1 file changed, 11 insertions(+), 7 deletions(-)
> > 
> > diff --git a/src/cam/main.cpp b/src/cam/main.cpp
> > index 4c2df583fe8e99b7..8df8844c33a2d052 100644
> > --- a/src/cam/main.cpp
> > +++ b/src/cam/main.cpp
> > @@ -133,6 +133,7 @@ static int capture()
> >  	int ret;
> >  
> >  	std::vector<Stream *> streams = camera->streams();
> > +	std::vector<Request *> requests;
> >  
> >  	ret = configureStreams(camera.get(), streams);
> >  	if (ret < 0) {
> > @@ -169,21 +170,24 @@ static int capture()
> >  			goto out;
> >  		}
> >  
> > -		ret = camera->queueRequest(request);
> > -		if (ret < 0) {
> > -			std::cerr << "Can't queue request" << std::endl;
> > -			goto out;
> > -		}
> > +		requests.push_back(request);
> >  	}
> >  
> > -	std::cout << "Capture until user interrupts by SIGINT" << std::endl;
> > -
> >  	ret = camera->start();
> >  	if (ret) {
> >  		std::cout << "Failed to start capture" << std::endl;
> >  		goto out;
> >  	}
> >  
> > +	for (Request *request : requests) {
> > +		ret = camera->queueRequest(request);
> > +		if (ret < 0) {
> > +			std::cerr << "Can't queue request" << std::endl;
> > +			goto out;
> > +		}
> > +	}
> > +
> > +	std::cout << "Capture until user interrupts by SIGINT" << std::endl;
> >  	ret = loop->exec();
> >  
> >  	ret = camera->stop();
> 
> -- 
> Regards,
> 
> Laurent Pinchart

-- 
Regards,
Niklas Söderlund