[PATCH v6 2/5] pipeline: simple: Connect/disconnect frameStart signal at start/stop time

[Stefan Klug]

Hi Stanislaw,

Thank you for the patch. 

On Wed, Mar 05, 2025 at 02:52:53PM +0100, Stanislaw Gruszka wrote:
> The frameStart signal from the frame start emitter is connected in the
> configure() function, and is never disconnected. This means that each
> time the camera is configured a new connection is made, causing the
> DelayedControls::applyControls() to be called multiple times. Fix it by
> connecting and disconnecting the signal when starting and stopping the
> camera.
> 
> Co-developed-by: Hans de Goede <hdegoede at redhat.com>
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> Co-developed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka at linux.intel.com>

Reviewed-by: Stefan Klug <stefan.klug at ideasonboard.com>

Cheers,
Stefan

> ---
>  src/libcamera/pipeline/simple/simple.cpp | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp
> index 6e039bf3..8345a771 100644
> --- a/src/libcamera/pipeline/simple/simple.cpp
> +++ b/src/libcamera/pipeline/simple/simple.cpp
> @@ -1285,8 +1285,6 @@ int SimplePipelineHandler::configure(Camera *camera, CameraConfiguration *c)
>  	data->delayedCtrls_ =
>  		std::make_unique<DelayedControls>(data->sensor_->device(),
>  						  params);
> -	data->video_->frameStart.connect(data->delayedCtrls_.get(),
> -					 &DelayedControls::applyControls);
>  
>  	StreamConfiguration inputCfg;
>  	inputCfg.pixelFormat = pipeConfig->captureFormat;
> @@ -1354,6 +1352,9 @@ int SimplePipelineHandler::start(Camera *camera, [[maybe_unused]] const ControlL
>  
>  	video->bufferReady.connect(data, &SimpleCameraData::imageBufferReady);
>  
> +	data->video_->frameStart.connect(data->delayedCtrls_.get(),
> +					 &DelayedControls::applyControls);
> +
>  	ret = video->streamOn();
>  	if (ret < 0) {
>  		stop(camera);
> @@ -1386,6 +1387,9 @@ void SimplePipelineHandler::stopDevice(Camera *camera)
>  	SimpleCameraData *data = cameraData(camera);
>  	V4L2VideoDevice *video = data->video_;
>  
> +	data->video_->frameStart.disconnect(data->delayedCtrls_.get(),
> +					    &DelayedControls::applyControls);
> +
>  	if (data->useConversion_) {
>  		if (data->converter_)
>  			data->converter_->stop();
> -- 
> 2.43.0
>