[libcamera-devel] [PATCH v2 3/8] libcamera: pipeline_handler: Notify Request queueing failure
Hirokazu Honda
hiroh at chromium.org
Mon May 17 06:48:59 CEST 2021
Hi Jacopo and Laurent,
On Mon, May 17, 2021 at 11:45 AM Laurent Pinchart <
laurent.pinchart at ideasonboard.com> wrote:
> Hi Jacopo,
>
> Thank you for the patch.
>
> On Thu, May 13, 2021 at 11:22:41AM +0200, Jacopo Mondi wrote:
> > Capture requests are queued by the PipelineHandler base class to each
> > pipeline handler implementation using the virtual queueRequestDevice()
> > function.
> >
> > However, if the pipeline handler fails to queue the request to the
> > hardware, the request gets silently deleted from the list of queued
> > ones, without notifying application of the error.
> >
> > Allowing applications to know if a Request has failed to queue
> > by emitting the Camera::bufferCompleted and Camera::requestCompleted
> > signals allows them to maintain a state consistent with the one
> > internal to the library.
> >
> > To do so, if queuing a request to the device fails, cancel the request
> > and emit the completion signal to report the failure to applications.
> >
> > Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> > ---
> > src/libcamera/pipeline_handler.cpp | 15 ++++++++++++++-
> > 1 file changed, 14 insertions(+), 1 deletion(-)
> >
> > diff --git a/src/libcamera/pipeline_handler.cpp
> b/src/libcamera/pipeline_handler.cpp
> > index f41b7a7b3308..260a52018a4d 100644
> > --- a/src/libcamera/pipeline_handler.cpp
> > +++ b/src/libcamera/pipeline_handler.cpp
> > @@ -391,6 +391,8 @@ bool PipelineHandler::hasPendingRequests(const
> Camera *camera) const
> > * This method queues a capture request to the pipeline handler for
> processing.
> > * The request is first added to the internal list of queued requests,
> and
> > * then passed to the pipeline handler with a call to
> queueRequestDevice().
> > + * If the pipeline handler fails in queuing the request to the hardware
> the
> > + * request is immediately completed with error.
> > *
> > * Keeping track of queued requests ensures automatic completion of all
> requests
> > * when the pipeline handler is stopped with stop(). Request completion
> shall be
> > @@ -409,8 +411,19 @@ void PipelineHandler::queueRequest(Request *request)
> > request->sequence_ = data->requestSequence_++;
> >
> > int ret = queueRequestDevice(camera, request);
> > - if (ret)
> > + if (ret) {
> > + /*
> > + * Cancel the request and notify completion of its buffers
> in
> > + * error state. Then complete the cancelled request and
> remove
> > + * it from the queued requests list.
> > + */
> > + request->cancel();
> > + for (auto bufferMap : request->buffers())
> > + camera->bufferCompleted.emit(request,
> bufferMap.second);
> > +
> > + camera->requestComplete(request);
>
> This breaks the request completion ordering. I think you could just call
> PipelineHandler::completeRequest() instead.
>
I had the same comment in the previous version.
https://patchwork.libcamera.org/patch/12243/
We were waiting for your reply. Alright we got the reply now.
> > data->queuedRequests_.remove(request);
> > + }
> > }
> >
> > /**
>
> --
> Regards,
>
> Laurent Pinchart
>
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