[libcamera-devel] [PATCH v3 11/11] libcamera: ipu3: Share parameter and statistic buffers with IPA

[Kieran Bingham]

On 04/02/2021 18:54, Laurent Pinchart wrote:
> Hi Niklas,
> 
> Thank you for the patch.
> 
> On Thu, Feb 04, 2021 at 05:29:43PM +0100, Niklas Söderlund wrote:
>> Use the IPU3Frames helper to share parameters and statistics buffers
>> with the IPA. Track which parameter and statistic buffer is used for
>> which request and make sure the parameter buffers is filled in by the
>> IPA before it's needed and that the statistic buffer is consumed and
>> meta data generated before completing the request.
>>
>> With this change the IPU3 pipeline is prepared to fully operate with an
>> IPA component.
>>
>> Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
>> ---
>> * Changes since v1
>> - Update commit message.
>> - s/frameInfo_/frameInfos_/
>> - Refactor away isComplete variable.
>>
>> * Changes since v2
>> - Emedd the IPU3Frames instance instead of allocating it.
>> - Use -ENOBUFS instead of _ENOENT in queueRequestDevice().
>> - Keep isComplete in cio2BufferReady()
>> - Rework the queue logic.
>> ---
>>  src/libcamera/pipeline/ipu3/ipu3.cpp | 149 ++++++++++++++++++++-------
>>  1 file changed, 112 insertions(+), 37 deletions(-)
>>
>> diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
>> index 092db6389833a481..b79db25050d2c1d6 100644
>> --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
>> +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
>> @@ -29,6 +29,7 @@
>>  #include "libcamera/internal/v4l2_controls.h"
>>  
>>  #include "cio2.h"
>> +#include "frames.h"
>>  #include "imgu.h"
>>  
>>  namespace libcamera {
>> @@ -61,6 +62,8 @@ public:
>>  
>>  	void imguOutputBufferReady(FrameBuffer *buffer);
>>  	void cio2BufferReady(FrameBuffer *buffer);
>> +	void paramBufferReady(FrameBuffer *buffer);
>> +	void statBufferReady(FrameBuffer *buffer);
>>  
>>  	CIO2Device cio2_;
>>  	ImgUDevice *imgu_;
>> @@ -71,6 +74,7 @@ public:
>>  
>>  	uint32_t exposureTime_;
>>  	std::unique_ptr<DelayedControls> delayedCtrls_;
>> +	IPU3Frames frameInfos_;
>>  
>>  private:
>>  	void queueFrameAction(unsigned int id, const IPAOperationData &op);
>> @@ -609,6 +613,8 @@ int PipelineHandlerIPU3::allocateBuffers(Camera *camera)
>>  
>>  	data->ipa_->mapBuffers(ipaBuffers_);
>>  
>> +	data->frameInfos_.init(imgu->paramBuffers_, imgu->statBuffers_);
>> +
>>  	return 0;
>>  }
>>  
>> @@ -616,6 +622,8 @@ int PipelineHandlerIPU3::freeBuffers(Camera *camera)
>>  {
>>  	IPU3CameraData *data = cameraData(camera);
>>  
>> +	data->frameInfos_.clear();
>> +
>>  	std::vector<unsigned int> ids;
>>  	for (IPABuffer &ipabuf : ipaBuffers_)
>>  		ids.push_back(ipabuf.id);
>> @@ -713,7 +721,10 @@ void PipelineHandlerIPU3::stop(Camera *camera)
>>  int PipelineHandlerIPU3::queueRequestDevice(Camera *camera, Request *request)
>>  {
>>  	IPU3CameraData *data = cameraData(camera);
>> -	int error = 0;
>> +
>> +	IPU3Frames::Info *info = data->frameInfos_.create(request);
>> +	if (!info)
>> +		return -ENOBUFS;
>>  
>>  	/*
>>  	 * Queue a buffer on the CIO2, using the raw stream buffer provided in
>> @@ -724,24 +735,9 @@ int PipelineHandlerIPU3::queueRequestDevice(Camera *camera, Request *request)
>>  	if (!rawBuffer)
>>  		return -ENOMEM;
> 
> What will happen to info in this case ? As there will be no raw buffer
> associated with it, won't it linger forever in a list ?
> 
>>  
>> -	/* Queue all buffers from the request aimed for the ImgU. */
>> -	for (auto it : request->buffers()) {
>> -		const Stream *stream = it.first;
>> -		FrameBuffer *buffer = it.second;
>> -		int ret;
>> +	info->rawBuffer = rawBuffer;
>>  
>> -		if (stream == &data->outStream_)
>> -			ret = data->imgu_->output_->queueBuffer(buffer);
>> -		else if (stream == &data->vfStream_)
>> -			ret = data->imgu_->viewfinder_->queueBuffer(buffer);
>> -		else
>> -			continue;
>> -
>> -		if (ret < 0)
>> -			error = ret;
>> -	}
>> -
>> -	return error;
>> +	return 0;
>>  }
>>  
>>  bool PipelineHandlerIPU3::match(DeviceEnumerator *enumerator)
>> @@ -1007,6 +1003,10 @@ int PipelineHandlerIPU3::registerCameras()
>>  					&IPU3CameraData::imguOutputBufferReady);
>>  		data->imgu_->viewfinder_->bufferReady.connect(data.get(),
>>  					&IPU3CameraData::imguOutputBufferReady);
>> +		data->imgu_->param_->bufferReady.connect(data.get(),
>> +					&IPU3CameraData::paramBufferReady);
>> +		data->imgu_->stat_->bufferReady.connect(data.get(),
>> +					&IPU3CameraData::statBufferReady);
>>  
>>  		/* Create and register the Camera instance. */
>>  		std::string cameraId = cio2->sensor()->id();
>> @@ -1039,7 +1039,7 @@ int IPU3CameraData::loadIPA()
>>  	return 0;
>>  }
>>  
>> -void IPU3CameraData::queueFrameAction([[maybe_unused]] unsigned int id,
>> +void IPU3CameraData::queueFrameAction(unsigned int id,
>>  				      const IPAOperationData &action)
>>  {
>>  	switch (action.operation) {
>> @@ -1048,6 +1048,41 @@ void IPU3CameraData::queueFrameAction([[maybe_unused]] unsigned int id,
>>  		delayedCtrls_->push(controls);
>>  		break;
>>  	}
>> +	case IPU3_IPA_ACTION_PARAM_FILLED: {
>> +		IPU3Frames::Info *info = frameInfos_.find(id);
>> +		if (!info)
>> +			break;
> 
> Should we warn in this case ? Maybe in IPU3Frames::info() itself to
> avoid duplicating log calls ? I'm tempted to even assert.
> 
>> +
>> +		/* Queue all buffers from the request aimed for the ImgU. */
>> +		for (auto it : info->request->buffers()) {
>> +			const Stream *stream = it.first;
>> +			FrameBuffer *outbuffer = it.second;
>> +
>> +			if (stream == &outStream_)
>> +				imgu_->output_->queueBuffer(outbuffer);
>> +			else if (stream == &vfStream_)
>> +				imgu_->viewfinder_->queueBuffer(outbuffer);
>> +		}
>> +
>> +		imgu_->param_->queueBuffer(info->paramBuffer);
>> +		imgu_->stat_->queueBuffer(info->statBuffer);
>> +		imgu_->input_->queueBuffer(info->rawBuffer);
>> +
>> +		break;
>> +	}
>> +	case IPU3_IPA_ACTION_METADATA_READY: {
>> +		IPU3Frames::Info *info = frameInfos_.find(id);
>> +		if (!info)
>> +			break;
>> +
>> +		Request *request = info->request;
>> +		request->metadata() = action.controls[0];
>> +		info->metadataProcessed = true;
>> +		if (frameInfos_.tryComplete(info))
>> +			pipe_->completeRequest(request);
> 
> Maybe we could pass the request to IPU3Frames, and handle completion
> automatically internally, but that's for later.
> 
>> +
>> +		break;
>> +	}
>>  	default:
>>  		LOG(IPU3, Error) << "Unknown action " << action.operation;
>>  		break;
>> @@ -1068,11 +1103,12 @@ void IPU3CameraData::imguOutputBufferReady(FrameBuffer *buffer)
>>  {
>>  	Request *request = buffer->request();
>>  
>> -	if (!pipe_->completeBuffer(request, buffer))
>> -		/* Request not completed yet, return here. */
>> +	pipe_->completeBuffer(request, buffer);
>> +
>> +	IPU3Frames::Info *info = frameInfos_.find(buffer);
>> +	if (!info)
>>  		return;
>>  
>> -	/* Mark the request as complete. */
>>  	request->metadata().set(controls::draft::PipelineDepth, 3);
>>  	/* \todo Move the ExposureTime control to the IPA. */
>>  	request->metadata().set(controls::ExposureTime, exposureTime_);
>> @@ -1081,7 +1117,12 @@ void IPU3CameraData::imguOutputBufferReady(FrameBuffer *buffer)
>>  		Rectangle cropRegion = request->controls().get(controls::ScalerCrop);
>>  		request->metadata().set(controls::ScalerCrop, cropRegion);
>>  	}
>> -	pipe_->completeRequest(request);
>> +
>> +	if (buffer->metadata().status == FrameMetadata::FrameCancelled)
>> +		info->metadataProcessed = true;
>> +
>> +	if (frameInfos_.tryComplete(info))
>> +		pipe_->completeRequest(request);
>>  }
>>  
>>  /**
>> @@ -1093,26 +1134,60 @@ void IPU3CameraData::imguOutputBufferReady(FrameBuffer *buffer)
>>   */
>>  void IPU3CameraData::cio2BufferReady(FrameBuffer *buffer)
>>  {
>> -	/* \todo Handle buffer failures when state is set to BufferError. */
>> -	if (buffer->metadata().status == FrameMetadata::FrameCancelled)
>> +	IPU3Frames::Info *info = frameInfos_.find(buffer);
>> +	if (!info)
>>  		return;
>>  
>>  	Request *request = buffer->request();
>>  
>> -	/*
>> -	 * If the request contains a buffer for the RAW stream only, complete it
>> -	 * now as there's no need for ImgU processing.
>> -	 */
>> -	if (request->findBuffer(&rawStream_)) {
>> -		bool isComplete = pipe_->completeBuffer(request, buffer);
>> -		if (isComplete) {
>> -			request->metadata().set(controls::draft::PipelineDepth, 2);
>> -			pipe_->completeRequest(request);
>> -			return;
>> -		}
>> +	if (request->findBuffer(&rawStream_))
>> +		pipe_->completeBuffer(request, buffer);
> 
> If you moved this after the next if (...) { } block, you could...
> 
>> +
>> +	/* If the buffer is cancelled force a complete of the whole request. */
>> +	if (buffer->metadata().status == FrameMetadata::FrameCancelled) {
>> +		for (auto it : request->buffers())
>> +			if (it.second != buffer)
> 
> ... drop this check.
> 
>> +				pipe_->completeBuffer(request, it.second);
>> +
>> +		info->paramDequeued = true;
>> +		info->metadataProcessed = true;
>> +		ASSERT(frameInfos_.tryComplete(info));
>> +		pipe_->completeRequest(request);
>> +
>> +		return;
>>  	}
>>  
>> -	imgu_->input_->queueBuffer(buffer);
>> +	IPAOperationData op;
>> +	op.operation = IPU3_IPA_EVENT_FILL_PARAMS;
>> +	op.data = { info->id, info->paramBuffer->cookie() };
>> +	op.controls = { request->controls() };
> 
> This is the right time to call IPU3_IPA_EVENT_FILL_PARAMS, but the
> request controls need to be passed to the IPA earlier, right when the
> request is queued, as the IPA needs to look ahead in the request queue
> to compute parameters.
> 
> This is the main issue in this patch, the rest is fairly minor.

Sounds like we need to add another call to the IPA on queueRequest time.

I'd be tempted to build that on top, as we're going to have to consider
how to handle when to run the IPA algorithms anyway.

My worry is running the algorithms, and then only getting the
statsistics back $QUEUE_LENGTH 'runs' later - but presumably that will
be handled by things like the sequence number, and the timestamps of the
completions. We'll see as we dig further I think.


> 
>> +	ipa_->processEvent(op);
>> +}
>> +
>> +void IPU3CameraData::paramBufferReady(FrameBuffer *buffer)
>> +{
>> +	IPU3Frames::Info *info = frameInfos_.find(buffer);
>> +	if (!info)
>> +		return;
>> +
>> +	info->paramDequeued = true;
>> +	if (frameInfos_.tryComplete(info))
>> +		pipe_->completeRequest(buffer->request());
>> +}
>> +
>> +void IPU3CameraData::statBufferReady(FrameBuffer *buffer)
>> +{
>> +	if (buffer->metadata().status == FrameMetadata::FrameCancelled)
>> +		return;
> 
> Why do we need to check for the status for stats buffers but not for
> params buffers ?

Aha! I bet we do :-) I started a rabbit-hole debugging where
completeRequest() was being called with nullptrs at shutdown.

I bet that was because the buffer->request() had been zeroed or was
unset when the buffers are cancelled.


> 
>> +
>> +	IPU3Frames::Info *info = frameInfos_.find(buffer);
>> +	if (!info)
>> +		return;
>> +
>> +	IPAOperationData op;
>> +	op.operation = IPU3_IPA_EVENT_STAT_READY;
>> +	op.data = { info->id, info->statBuffer->cookie() };
>> +	ipa_->processEvent(op);
>>  }
>>  
>>  REGISTER_PIPELINE_HANDLER(PipelineHandlerIPU3)
> 

-- 
Regards
--
Kieran