[libcamera-devel,v3,19/22] libcamera: pipeline: rkisp1: Move start and stop of path to RkISP1Path
diff mbox series

Message ID 20200925014207.1455796-20-niklas.soderlund@ragnatech.se
State Accepted
Headers show
Series
  • libcamera: pipeline: rkisp1: Extend to support two streams
Related show

Commit Message

Niklas Söderlund Sept. 25, 2020, 1:42 a.m. UTC 
Move the start and stop of a path to RkISP1Path. This allows the
importing of buffers to be moved closer the path start/stop simplifying
the code. Also by adding a simple running tracker the error logic in
PipelineHandlerRkISP1 can be simplified as stop() can always be called.

This also removes all external users of RkISP1Path::video_ so it can be
made private.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
---
 src/libcamera/pipeline/rkisp1/rkisp1.cpp     | 53 ++------------------
 src/libcamera/pipeline/rkisp1/rkisp1path.cpp | 42 +++++++++++++++-
 src/libcamera/pipeline/rkisp1/rkisp1path.h   |  8 +--
 3 files changed, 50 insertions(+), 53 deletions(-)

Comments

Laurent Pinchart Sept. 28, 2020, 10:46 p.m. UTC | #1 
Hi Niklas,

Thank you for the patch.

On Fri, Sep 25, 2020 at 03:42:04AM +0200, Niklas Söderlund wrote:
> Move the start and stop of a path to RkISP1Path. This allows the
> importing of buffers to be moved closer the path start/stop simplifying
> the code. Also by adding a simple running tracker the error logic in
> PipelineHandlerRkISP1 can be simplified as stop() can always be called.
> 
> This also removes all external users of RkISP1Path::video_ so it can be
> made private.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
> ---
>  src/libcamera/pipeline/rkisp1/rkisp1.cpp     | 53 ++------------------
>  src/libcamera/pipeline/rkisp1/rkisp1path.cpp | 42 +++++++++++++++-
>  src/libcamera/pipeline/rkisp1/rkisp1path.h   |  8 +--
>  3 files changed, 50 insertions(+), 53 deletions(-)
> 
> diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> index 7dd4fb11c39dd811..6158fbee41339c32 100644
> --- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> +++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> @@ -770,20 +770,6 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
>  		data->selfPathStream_.configuration().bufferCount,
>  	});
>  
> -	if (data->mainPathActive_) {
> -		ret = mainPath_.video_->importBuffers(
> -			data->mainPathStream_.configuration().bufferCount);
> -		if (ret < 0)
> -			goto error;
> -	}
> -
> -	if (data->selfPathActive_) {
> -		ret = selfPath_.video_->importBuffers(
> -			data->selfPathStream_.configuration().bufferCount);
> -		if (ret < 0)
> -			goto error;
> -	}
> -
>  	ret = param_->allocateBuffers(maxCount, &paramBuffers_);
>  	if (ret < 0)
>  		goto error;
> @@ -813,8 +799,6 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
>  error:
>  	paramBuffers_.clear();
>  	statBuffers_.clear();
> -	mainPath_.video_->releaseBuffers();
> -	selfPath_.video_->releaseBuffers();
>  
>  	return ret;
>  }
> @@ -845,12 +829,6 @@ int PipelineHandlerRkISP1::freeBuffers(Camera *camera)
>  	if (stat_->releaseBuffers())
>  		LOG(RkISP1, Error) << "Failed to release stat buffers";
>  
> -	if (mainPath_.video_->releaseBuffers())
> -		LOG(RkISP1, Error) << "Failed to release main path buffers";
> -
> -	if (selfPath_.video_->releaseBuffers())
> -		LOG(RkISP1, Error) << "Failed to release self path buffers";
> -
>  	return 0;
>  }
>  
> @@ -896,15 +874,12 @@ int PipelineHandlerRkISP1::start(Camera *camera)
>  	std::map<unsigned int, IPAStream> streamConfig;
>  
>  	if (data->mainPathActive_) {
> -		ret = mainPath_.video_->streamOn();
> +		ret = mainPath_.start();
>  		if (ret) {
>  			param_->streamOff();
>  			stat_->streamOff();
>  			data->ipa_->stop();
>  			freeBuffers(camera);
> -
> -			LOG(RkISP1, Error)
> -				<< "Failed to start main path " << camera->id();
>  			return ret;
>  		}
>  
> @@ -915,18 +890,13 @@ int PipelineHandlerRkISP1::start(Camera *camera)
>  	}
>  
>  	if (data->selfPathActive_) {
> -		ret = selfPath_.video_->streamOn();
> +		ret = selfPath_.start();
>  		if (ret) {
> -			if (data->mainPathActive_)
> -				mainPath_.video_->streamOff();
> -
> +			mainPath_.stop();
>  			param_->streamOff();
>  			stat_->streamOff();
>  			data->ipa_->stop();
>  			freeBuffers(camera);
> -
> -			LOG(RkISP1, Error)
> -				<< "Failed to start self path " << camera->id();
>  			return ret;
>  		}
>  
> @@ -963,21 +933,8 @@ void PipelineHandlerRkISP1::stop(Camera *camera)
>  	RkISP1CameraData *data = cameraData(camera);
>  	int ret;
>  
> -	if (data->selfPathActive_) {
> -		ret = selfPath_.video_->streamOff();
> -		if (ret)
> -			LOG(RkISP1, Warning)
> -				<< "Failed to stop self path for "
> -				<< camera->id();
> -	}
> -
> -	if (data->mainPathActive_) {
> -		ret = mainPath_.video_->streamOff();
> -		if (ret)
> -			LOG(RkISP1, Warning)
> -				<< "Failed to stop main path for "
> -				<< camera->id();
> -	}
> +	selfPath_.stop();
> +	mainPath_.stop();
>  
>  	ret = stat_->streamOff();
>  	if (ret)
> diff --git a/src/libcamera/pipeline/rkisp1/rkisp1path.cpp b/src/libcamera/pipeline/rkisp1/rkisp1path.cpp
> index 74eaa5d32388184b..b2dd669f4caf3269 100644
> --- a/src/libcamera/pipeline/rkisp1/rkisp1path.cpp
> +++ b/src/libcamera/pipeline/rkisp1/rkisp1path.cpp
> @@ -20,9 +20,9 @@ LOG_DECLARE_CATEGORY(RkISP1)
>  
>  RkISP1Path::RkISP1Path(const char *name, const std::vector<PixelFormat> &formats,
>  		       const Size &minResolution, const Size &maxResolution)
> -	: video_(nullptr), name_(name), formats_(formats),
> +	: name_(name), running_(false), formats_(formats),
>  	  minResolution_(minResolution), maxResolution_(maxResolution),
> -	  resizer_(nullptr)
> +	  resizer_(nullptr), video_(nullptr)
>  {
>  }
>  
> @@ -155,6 +155,44 @@ int RkISP1Path::exportBuffers(unsigned int bufferCount,
>  	return video_->exportBuffers(bufferCount, buffers);
>  }
>  
> +int RkISP1Path::start()
> +{
> +	int ret;
> +
> +	if (running_)
> +		return -EBUSY;
> +
> +	ret = video_->importBuffers(RKISP1_BUFFER_COUNT);

This is a functional change that needs to be documented in the commit
message (the number of buffers is now hardcoded). Is it right ?

> +	if (ret)
> +		return ret;
> +
> +	ret = video_->streamOn();
> +	if (ret) {
> +		LOG(RkISP1, Error)
> +			<< "Failed to start " << name_ << "path";

Should it be " path" ? Same below.

> +
> +		video_->releaseBuffers();
> +		return ret;
> +	}
> +
> +	running_ = true;
> +
> +	return 0;
> +}
> +
> +void RkISP1Path::stop()
> +{
> +	if (!running_)
> +		return;
> +
> +	if (video_->streamOff())
> +		LOG(RkISP1, Warning) << "Failed to stop " << name_ << "path";
> +
> +	video_->releaseBuffers();
> +
> +	running_ = false;
> +}
> +
>  RkISP1MainPath::RkISP1MainPath()
>  	: RkISP1Path("main",
>  		     {
> diff --git a/src/libcamera/pipeline/rkisp1/rkisp1path.h b/src/libcamera/pipeline/rkisp1/rkisp1path.h
> index 1315b2c64feac681..9c2ecb620375683b 100644
> --- a/src/libcamera/pipeline/rkisp1/rkisp1path.h
> +++ b/src/libcamera/pipeline/rkisp1/rkisp1path.h
> @@ -41,22 +41,24 @@ public:
>  	int exportBuffers(unsigned int bufferCount,
>  			  std::vector<std::unique_ptr<FrameBuffer>> *buffers);
>  
> +	int start();
> +	void stop();
> +
>  	int queueBuffer(FrameBuffer *buffer) { return video_->queueBuffer(buffer); }
>  	Signal<FrameBuffer *> &bufferReady() { return video_->bufferReady; }
>  
> -	/* \todo Make video private. */
> -	V4L2VideoDevice *video_;
> -
>  private:
>  	static constexpr unsigned int RKISP1_BUFFER_COUNT = 4;
>  
>  	const char *name_;
> +	bool running_;
>  
>  	const std::vector<PixelFormat> formats_;
>  	const Size minResolution_;
>  	const Size maxResolution_;
>  
>  	V4L2Subdevice *resizer_;
> +	V4L2VideoDevice *video_;
>  };
>  
>  class RkISP1MainPath : public RkISP1Path
Niklas Söderlund Sept. 28, 2020, 10:57 p.m. UTC | #2 
Hi Laurent,

Thanks for your feedback.

On 2020-09-29 01:46:47 +0300, Laurent Pinchart wrote:
> Hi Niklas,
> 
> Thank you for the patch.
> 
> On Fri, Sep 25, 2020 at 03:42:04AM +0200, Niklas Söderlund wrote:
> > Move the start and stop of a path to RkISP1Path. This allows the
> > importing of buffers to be moved closer the path start/stop simplifying
> > the code. Also by adding a simple running tracker the error logic in
> > PipelineHandlerRkISP1 can be simplified as stop() can always be called.
> > 
> > This also removes all external users of RkISP1Path::video_ so it can be
> > made private.
> > 
> > Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
> > ---
> >  src/libcamera/pipeline/rkisp1/rkisp1.cpp     | 53 ++------------------
> >  src/libcamera/pipeline/rkisp1/rkisp1path.cpp | 42 +++++++++++++++-
> >  src/libcamera/pipeline/rkisp1/rkisp1path.h   |  8 +--
> >  3 files changed, 50 insertions(+), 53 deletions(-)
> > 
> > diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> > index 7dd4fb11c39dd811..6158fbee41339c32 100644
> > --- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> > +++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> > @@ -770,20 +770,6 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
> >  		data->selfPathStream_.configuration().bufferCount,
> >  	});
> >  
> > -	if (data->mainPathActive_) {
> > -		ret = mainPath_.video_->importBuffers(
> > -			data->mainPathStream_.configuration().bufferCount);
> > -		if (ret < 0)
> > -			goto error;
> > -	}
> > -
> > -	if (data->selfPathActive_) {
> > -		ret = selfPath_.video_->importBuffers(
> > -			data->selfPathStream_.configuration().bufferCount);
> > -		if (ret < 0)
> > -			goto error;
> > -	}
> > -
> >  	ret = param_->allocateBuffers(maxCount, &paramBuffers_);
> >  	if (ret < 0)
> >  		goto error;
> > @@ -813,8 +799,6 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
> >  error:
> >  	paramBuffers_.clear();
> >  	statBuffers_.clear();
> > -	mainPath_.video_->releaseBuffers();
> > -	selfPath_.video_->releaseBuffers();
> >  
> >  	return ret;
> >  }
> > @@ -845,12 +829,6 @@ int PipelineHandlerRkISP1::freeBuffers(Camera *camera)
> >  	if (stat_->releaseBuffers())
> >  		LOG(RkISP1, Error) << "Failed to release stat buffers";
> >  
> > -	if (mainPath_.video_->releaseBuffers())
> > -		LOG(RkISP1, Error) << "Failed to release main path buffers";
> > -
> > -	if (selfPath_.video_->releaseBuffers())
> > -		LOG(RkISP1, Error) << "Failed to release self path buffers";
> > -
> >  	return 0;
> >  }
> >  
> > @@ -896,15 +874,12 @@ int PipelineHandlerRkISP1::start(Camera *camera)
> >  	std::map<unsigned int, IPAStream> streamConfig;
> >  
> >  	if (data->mainPathActive_) {
> > -		ret = mainPath_.video_->streamOn();
> > +		ret = mainPath_.start();
> >  		if (ret) {
> >  			param_->streamOff();
> >  			stat_->streamOff();
> >  			data->ipa_->stop();
> >  			freeBuffers(camera);
> > -
> > -			LOG(RkISP1, Error)
> > -				<< "Failed to start main path " << camera->id();
> >  			return ret;
> >  		}
> >  
> > @@ -915,18 +890,13 @@ int PipelineHandlerRkISP1::start(Camera *camera)
> >  	}
> >  
> >  	if (data->selfPathActive_) {
> > -		ret = selfPath_.video_->streamOn();
> > +		ret = selfPath_.start();
> >  		if (ret) {
> > -			if (data->mainPathActive_)
> > -				mainPath_.video_->streamOff();
> > -
> > +			mainPath_.stop();
> >  			param_->streamOff();
> >  			stat_->streamOff();
> >  			data->ipa_->stop();
> >  			freeBuffers(camera);
> > -
> > -			LOG(RkISP1, Error)
> > -				<< "Failed to start self path " << camera->id();
> >  			return ret;
> >  		}
> >  
> > @@ -963,21 +933,8 @@ void PipelineHandlerRkISP1::stop(Camera *camera)
> >  	RkISP1CameraData *data = cameraData(camera);
> >  	int ret;
> >  
> > -	if (data->selfPathActive_) {
> > -		ret = selfPath_.video_->streamOff();
> > -		if (ret)
> > -			LOG(RkISP1, Warning)
> > -				<< "Failed to stop self path for "
> > -				<< camera->id();
> > -	}
> > -
> > -	if (data->mainPathActive_) {
> > -		ret = mainPath_.video_->streamOff();
> > -		if (ret)
> > -			LOG(RkISP1, Warning)
> > -				<< "Failed to stop main path for "
> > -				<< camera->id();
> > -	}
> > +	selfPath_.stop();
> > +	mainPath_.stop();
> >  
> >  	ret = stat_->streamOff();
> >  	if (ret)
> > diff --git a/src/libcamera/pipeline/rkisp1/rkisp1path.cpp b/src/libcamera/pipeline/rkisp1/rkisp1path.cpp
> > index 74eaa5d32388184b..b2dd669f4caf3269 100644
> > --- a/src/libcamera/pipeline/rkisp1/rkisp1path.cpp
> > +++ b/src/libcamera/pipeline/rkisp1/rkisp1path.cpp
> > @@ -20,9 +20,9 @@ LOG_DECLARE_CATEGORY(RkISP1)
> >  
> >  RkISP1Path::RkISP1Path(const char *name, const std::vector<PixelFormat> &formats,
> >  		       const Size &minResolution, const Size &maxResolution)
> > -	: video_(nullptr), name_(name), formats_(formats),
> > +	: name_(name), running_(false), formats_(formats),
> >  	  minResolution_(minResolution), maxResolution_(maxResolution),
> > -	  resizer_(nullptr)
> > +	  resizer_(nullptr), video_(nullptr)
> >  {
> >  }
> >  
> > @@ -155,6 +155,44 @@ int RkISP1Path::exportBuffers(unsigned int bufferCount,
> >  	return video_->exportBuffers(bufferCount, buffers);
> >  }
> >  
> > +int RkISP1Path::start()
> > +{
> > +	int ret;
> > +
> > +	if (running_)
> > +		return -EBUSY;
> > +
> > +	ret = video_->importBuffers(RKISP1_BUFFER_COUNT);
> 
> This is a functional change that needs to be documented in the commit
> message (the number of buffers is now hardcoded). Is it right ?

No it's not the validate() function have always forced the number of 
buffers 4 or at other parts in the code to RKISP1_BUFFER_COUNT (which is 
defined as 4). This change only makes this more explicit.

I agree this is not the optimum behavior and we should rework the 
pipeline to accept a configurable number of buffers from the 
application. I wanted to keep the changes to a minimum as this series is 
already too large, but I have noted this in my todo file.

> 
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = video_->streamOn();
> > +	if (ret) {
> > +		LOG(RkISP1, Error)
> > +			<< "Failed to start " << name_ << "path";
> 
> Should it be " path" ? Same below.

Yes, thanks good catch.

> 
> > +
> > +		video_->releaseBuffers();
> > +		return ret;
> > +	}
> > +
> > +	running_ = true;
> > +
> > +	return 0;
> > +}
> > +
> > +void RkISP1Path::stop()
> > +{
> > +	if (!running_)
> > +		return;
> > +
> > +	if (video_->streamOff())
> > +		LOG(RkISP1, Warning) << "Failed to stop " << name_ << "path";
> > +
> > +	video_->releaseBuffers();
> > +
> > +	running_ = false;
> > +}
> > +
> >  RkISP1MainPath::RkISP1MainPath()
> >  	: RkISP1Path("main",
> >  		     {
> > diff --git a/src/libcamera/pipeline/rkisp1/rkisp1path.h b/src/libcamera/pipeline/rkisp1/rkisp1path.h
> > index 1315b2c64feac681..9c2ecb620375683b 100644
> > --- a/src/libcamera/pipeline/rkisp1/rkisp1path.h
> > +++ b/src/libcamera/pipeline/rkisp1/rkisp1path.h
> > @@ -41,22 +41,24 @@ public:
> >  	int exportBuffers(unsigned int bufferCount,
> >  			  std::vector<std::unique_ptr<FrameBuffer>> *buffers);
> >  
> > +	int start();
> > +	void stop();
> > +
> >  	int queueBuffer(FrameBuffer *buffer) { return video_->queueBuffer(buffer); }
> >  	Signal<FrameBuffer *> &bufferReady() { return video_->bufferReady; }
> >  
> > -	/* \todo Make video private. */
> > -	V4L2VideoDevice *video_;
> > -
> >  private:
> >  	static constexpr unsigned int RKISP1_BUFFER_COUNT = 4;
> >  
> >  	const char *name_;
> > +	bool running_;
> >  
> >  	const std::vector<PixelFormat> formats_;
> >  	const Size minResolution_;
> >  	const Size maxResolution_;
> >  
> >  	V4L2Subdevice *resizer_;
> > +	V4L2VideoDevice *video_;
> >  };
> >  
> >  class RkISP1MainPath : public RkISP1Path
> 
> -- 
> Regards,
> 
> Laurent Pinchart

Patch
diff mbox series 

diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
index 7dd4fb11c39dd811..6158fbee41339c32 100644
--- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
+++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
@@ -770,20 +770,6 @@  int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
 		data->selfPathStream_.configuration().bufferCount,
 	});
 
-	if (data->mainPathActive_) {
-		ret = mainPath_.video_->importBuffers(
-			data->mainPathStream_.configuration().bufferCount);
-		if (ret < 0)
-			goto error;
-	}
-
-	if (data->selfPathActive_) {
-		ret = selfPath_.video_->importBuffers(
-			data->selfPathStream_.configuration().bufferCount);
-		if (ret < 0)
-			goto error;
-	}
-
 	ret = param_->allocateBuffers(maxCount, &paramBuffers_);
 	if (ret < 0)
 		goto error;
@@ -813,8 +799,6 @@  int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
 error:
 	paramBuffers_.clear();
 	statBuffers_.clear();
-	mainPath_.video_->releaseBuffers();
-	selfPath_.video_->releaseBuffers();
 
 	return ret;
 }
@@ -845,12 +829,6 @@  int PipelineHandlerRkISP1::freeBuffers(Camera *camera)
 	if (stat_->releaseBuffers())
 		LOG(RkISP1, Error) << "Failed to release stat buffers";
 
-	if (mainPath_.video_->releaseBuffers())
-		LOG(RkISP1, Error) << "Failed to release main path buffers";
-
-	if (selfPath_.video_->releaseBuffers())
-		LOG(RkISP1, Error) << "Failed to release self path buffers";
-
 	return 0;
 }
 
@@ -896,15 +874,12 @@  int PipelineHandlerRkISP1::start(Camera *camera)
 	std::map<unsigned int, IPAStream> streamConfig;
 
 	if (data->mainPathActive_) {
-		ret = mainPath_.video_->streamOn();
+		ret = mainPath_.start();
 		if (ret) {
 			param_->streamOff();
 			stat_->streamOff();
 			data->ipa_->stop();
 			freeBuffers(camera);
-
-			LOG(RkISP1, Error)
-				<< "Failed to start main path " << camera->id();
 			return ret;
 		}
 
@@ -915,18 +890,13 @@  int PipelineHandlerRkISP1::start(Camera *camera)
 	}
 
 	if (data->selfPathActive_) {
-		ret = selfPath_.video_->streamOn();
+		ret = selfPath_.start();
 		if (ret) {
-			if (data->mainPathActive_)
-				mainPath_.video_->streamOff();
-
+			mainPath_.stop();
 			param_->streamOff();
 			stat_->streamOff();
 			data->ipa_->stop();
 			freeBuffers(camera);
-
-			LOG(RkISP1, Error)
-				<< "Failed to start self path " << camera->id();
 			return ret;
 		}
 
@@ -963,21 +933,8 @@  void PipelineHandlerRkISP1::stop(Camera *camera)
 	RkISP1CameraData *data = cameraData(camera);
 	int ret;
 
-	if (data->selfPathActive_) {
-		ret = selfPath_.video_->streamOff();
-		if (ret)
-			LOG(RkISP1, Warning)
-				<< "Failed to stop self path for "
-				<< camera->id();
-	}
-
-	if (data->mainPathActive_) {
-		ret = mainPath_.video_->streamOff();
-		if (ret)
-			LOG(RkISP1, Warning)
-				<< "Failed to stop main path for "
-				<< camera->id();
-	}
+	selfPath_.stop();
+	mainPath_.stop();
 
 	ret = stat_->streamOff();
 	if (ret)
diff --git a/src/libcamera/pipeline/rkisp1/rkisp1path.cpp b/src/libcamera/pipeline/rkisp1/rkisp1path.cpp
index 74eaa5d32388184b..b2dd669f4caf3269 100644
--- a/src/libcamera/pipeline/rkisp1/rkisp1path.cpp
+++ b/src/libcamera/pipeline/rkisp1/rkisp1path.cpp
@@ -20,9 +20,9 @@  LOG_DECLARE_CATEGORY(RkISP1)
 
 RkISP1Path::RkISP1Path(const char *name, const std::vector<PixelFormat> &formats,
 		       const Size &minResolution, const Size &maxResolution)
-	: video_(nullptr), name_(name), formats_(formats),
+	: name_(name), running_(false), formats_(formats),
 	  minResolution_(minResolution), maxResolution_(maxResolution),
-	  resizer_(nullptr)
+	  resizer_(nullptr), video_(nullptr)
 {
 }
 
@@ -155,6 +155,44 @@  int RkISP1Path::exportBuffers(unsigned int bufferCount,
 	return video_->exportBuffers(bufferCount, buffers);
 }
 
+int RkISP1Path::start()
+{
+	int ret;
+
+	if (running_)
+		return -EBUSY;
+
+	ret = video_->importBuffers(RKISP1_BUFFER_COUNT);
+	if (ret)
+		return ret;
+
+	ret = video_->streamOn();
+	if (ret) {
+		LOG(RkISP1, Error)
+			<< "Failed to start " << name_ << "path";
+
+		video_->releaseBuffers();
+		return ret;
+	}
+
+	running_ = true;
+
+	return 0;
+}
+
+void RkISP1Path::stop()
+{
+	if (!running_)
+		return;
+
+	if (video_->streamOff())
+		LOG(RkISP1, Warning) << "Failed to stop " << name_ << "path";
+
+	video_->releaseBuffers();
+
+	running_ = false;
+}
+
 RkISP1MainPath::RkISP1MainPath()
 	: RkISP1Path("main",
 		     {
diff --git a/src/libcamera/pipeline/rkisp1/rkisp1path.h b/src/libcamera/pipeline/rkisp1/rkisp1path.h
index 1315b2c64feac681..9c2ecb620375683b 100644
--- a/src/libcamera/pipeline/rkisp1/rkisp1path.h
+++ b/src/libcamera/pipeline/rkisp1/rkisp1path.h
@@ -41,22 +41,24 @@  public:
 	int exportBuffers(unsigned int bufferCount,
 			  std::vector<std::unique_ptr<FrameBuffer>> *buffers);
 
+	int start();
+	void stop();
+
 	int queueBuffer(FrameBuffer *buffer) { return video_->queueBuffer(buffer); }
 	Signal<FrameBuffer *> &bufferReady() { return video_->bufferReady; }
 
-	/* \todo Make video private. */
-	V4L2VideoDevice *video_;
-
 private:
 	static constexpr unsigned int RKISP1_BUFFER_COUNT = 4;
 
 	const char *name_;
+	bool running_;
 
 	const std::vector<PixelFormat> formats_;
 	const Size minResolution_;
 	const Size maxResolution_;
 
 	V4L2Subdevice *resizer_;
+	V4L2VideoDevice *video_;
 };
 
 class RkISP1MainPath : public RkISP1Path