[libcamera-devel] [PATCH 8/8] libcamera: camera: make sure camera is configured before starting

[Jacopo Mondi]

Hi Niklas,

On Tue, Feb 26, 2019 at 08:08:54PM +0100, Niklas Söderlund wrote:
> Hi Jacopo,
>
> Thanks for your feedback.
>
> On 2019-02-26 18:21:26 +0100, Jacopo Mondi wrote:
> > Hi Niklas,
> >
> > On Tue, Feb 26, 2019 at 03:18:57AM +0100, Niklas Söderlund wrote:
> > > If the camera is not configured there is little use to start it. Add a
> > > check to make sure the camera is configured before it's started.
> > >
> >
> > As commented on the previous patch, shouldn't this (and more..)
> > be caught by the state machine?
>
> If we introduce a Configured state sometime in the future this could be
> replaced with such a check. As I replied earlier, this series aim is to
> enforce the current behavior and what have been discussed. Currently
> there is no way for an application to un-configure a camera so adding
> such a state now is not possible.
>

It was my intention to start discussing if we want an explicit
'unconfigure' step, that would make sure 'allocate' and 'free' buffers
could only be called on a configured Camera (and possible hide 'free'
(and allocate?) completely from the application).

If you do consider this is not the right time to do so, please add my

Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>

> >
> > Thanks
> >   j
> >
> >
> > > Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> > > ---
> > >  src/libcamera/camera.cpp | 7 +++++++
> > >  1 file changed, 7 insertions(+)
> > >
> > > diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp
> > > index ba8638009992170f..cbc34599d25e5ed5 100644
> > > --- a/src/libcamera/camera.cpp
> > > +++ b/src/libcamera/camera.cpp
> > > @@ -423,12 +423,19 @@ int Camera::queueRequest(Request *request)
> > >   *
> > >   * \return 0 on success or a negative error code
> > >   * \retval -EACCES The camera is not in a state where it can be started.
> > > + * \retval -EINVAL The camera is not configured.
> > >   */
> > >  int Camera::start()
> > >  {
> > >  	if (!stateIs(Acquired))
> > >  		return -EACCES;
> > >
> > > +	if (activeStreams_.empty()) {
> > > +		LOG(Camera, Error)
> > > +			<< "Can't start camera without configuration";
> > > +		return -EINVAL;
> > > +	}
> > > +
> > >  	LOG(Camera, Debug) << "Starting capture";
> > >
> > >  	int ret = pipe_->start(this);
> > > --
> > > 2.20.1
> > >
> > > _______________________________________________
> > > libcamera-devel mailing list
> > > libcamera-devel at lists.libcamera.org
> > > https://lists.libcamera.org/listinfo/libcamera-devel
>
>
>
> --
> Regards,
> Niklas Söderlund
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