3 files changed, 60 insertions, 72 deletions

diff --git a/src/libcamera/pipeline/ipu3/cio2.cpp b/src/libcamera/pipeline/ipu3/cio2.cpp
index d698cd80..885e2ca0 100644
--- a/src/libcamera/pipeline/ipu3/cio2.cpp
+++ b/src/libcamera/pipeline/ipu3/cio2.cpp
@@ -213,31 +213,16 @@ int CIO2Device::exportBuffers(unsigned int count,
 	return output_->exportBuffers(count, buffers);
 }
 
-FrameBuffer *CIO2Device::getBuffer()
-{
-	if (availableBuffers_.empty()) {
-		LOG(IPU3, Error) << "CIO2 buffer underrun";
-		return nullptr;
-	}
-
-	FrameBuffer *buffer = availableBuffers_.front();
-
-	availableBuffers_.pop();
-
-	return buffer;
-}
-
-void CIO2Device::putBuffer(FrameBuffer *buffer)
-{
-	availableBuffers_.push(buffer);
-}
-
 int CIO2Device::start()
 {
-	int ret = output_->allocateBuffers(CIO2_BUFFER_COUNT, &buffers_);
+	int ret = output_->exportBuffers(CIO2_BUFFER_COUNT, &buffers_);
 	if (ret < 0)
 		return ret;
 
+	ret = output_->importBuffers(CIO2_BUFFER_COUNT);
+	if (ret)
+		LOG(IPU3, Error) << "Failed to import CIO2 buffers";
+
 	for (std::unique_ptr<FrameBuffer> &buffer : buffers_)
 		availableBuffers_.push(buffer.get());
 
@@ -257,11 +242,42 @@ int CIO2Device::stop()
 	return ret;
 }
 
-int CIO2Device::queueBuffer(FrameBuffer *buffer)
+int CIO2Device::queueBuffer(Request *request, FrameBuffer *rawBuffer)
 {
+	FrameBuffer *buffer = rawBuffer;
+
+	/* If no buffer is provided in the request, use an internal one. */
+	if (!buffer) {
+		if (availableBuffers_.empty()) {
+			LOG(IPU3, Error) << "CIO2 buffer underrun";
+			return -EINVAL;
+		}
+
+		buffer = availableBuffers_.front();
+		availableBuffers_.pop();
+	}
+
+	buffer->setRequest(request);
+
 	return output_->queueBuffer(buffer);
 }
 
+void CIO2Device::tryReturnBuffer(FrameBuffer *buffer)
+{
+	/*
+	 * \todo Once more pipelines deal with buffers that may be allocated
+	 * internally or externally this pattern might become a common need. At
+	 * that point this check should be moved to something clever in
+	 * FrameBuffer.
+	 */
+	for (const std::unique_ptr<FrameBuffer> &buf : buffers_) {
+		if (buf.get() == buffer) {
+			availableBuffers_.push(buffer);
+			break;
+		}
+	}
+}
+
 void CIO2Device::freeBuffers()
 {
 	/* The default std::queue constructor is explicit with gcc 5 and 6. */
diff --git a/src/libcamera/pipeline/ipu3/cio2.h b/src/libcamera/pipeline/ipu3/cio2.h
index 47c6f010..dc764b10 100644
--- a/src/libcamera/pipeline/ipu3/cio2.h
+++ b/src/libcamera/pipeline/ipu3/cio2.h
@@ -18,6 +18,7 @@ namespace libcamera {
 class CameraSensor;
 class FrameBuffer;
 class MediaDevice;
+class Request;
 class V4L2DeviceFormat;
 class V4L2Subdevice;
 class V4L2VideoDevice;
@@ -40,15 +41,13 @@ public:
 	int exportBuffers(unsigned int count,
 			  std::vector<std::unique_ptr<FrameBuffer>> *buffers);
 
-	FrameBuffer *getBuffer();
-	void putBuffer(FrameBuffer *buffer);
-
 	int start();
 	int stop();
 
 	CameraSensor *sensor() { return sensor_; }
 
-	int queueBuffer(FrameBuffer *buffer);
+	int queueBuffer(Request *request, FrameBuffer *rawBuffer);
+	void tryReturnBuffer(FrameBuffer *buffer);
 	Signal<FrameBuffer *> bufferReady;
 
 private:
diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
index 4818027e..6c43169e 100644
--- a/src/libcamera/pipeline/ipu3/ipu3.cpp
+++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
@@ -122,7 +122,6 @@ public:
 	}
 
 	void imguOutputBufferReady(FrameBuffer *buffer);
-	void imguInputBufferReady(FrameBuffer *buffer);
 	void cio2BufferReady(FrameBuffer *buffer);
 
 	CIO2Device cio2_;
@@ -737,25 +736,24 @@ void PipelineHandlerIPU3::stop(Camera *camera)
 int PipelineHandlerIPU3::queueRequestDevice(Camera *camera, Request *request)
 {
 	IPU3CameraData *data = cameraData(camera);
-	FrameBuffer *buffer;
 	int error = 0;
 
-	/* Get a CIO2 buffer, associate it with the request and queue it. */
-	buffer = data->cio2_.getBuffer();
-	if (!buffer)
-		return -EINVAL;
-
-	buffer->setRequest(request);
-	data->cio2_.queueBuffer(buffer);
+	/*
+	 * Queue a buffer on the CIO2, using the raw stream buffer provided in
+	 * the request, if any, or a CIO2 internal buffer otherwise.
+	 */
+	FrameBuffer *rawBuffer = request->findBuffer(&data->rawStream_);
+	error = data->cio2_.queueBuffer(request, rawBuffer);
+	if (error)
+		return error;
 
+	/* Queue all buffers from the request aimed for the ImgU. */
 	for (auto it : request->buffers()) {
 		IPU3Stream *stream = static_cast<IPU3Stream *>(it.first);
-		buffer = it.second;
-
-		/* Skip raw streams, they are copied from the CIO2 buffer. */
 		if (stream->raw_)
 			continue;
 
+		FrameBuffer *buffer = it.second;
 		int ret = stream->device_->dev->queueBuffer(buffer);
 		if (ret < 0)
 			error = ret;
@@ -885,8 +883,8 @@ int PipelineHandlerIPU3::registerCameras()
 		 */
 		data->cio2_.bufferReady.connect(data.get(),
 					&IPU3CameraData::cio2BufferReady);
-		data->imgu_->input_->bufferReady.connect(data.get(),
-					&IPU3CameraData::imguInputBufferReady);
+		data->imgu_->input_->bufferReady.connect(&data->cio2_,
+					&CIO2Device::tryReturnBuffer);
 		data->imgu_->output_.dev->bufferReady.connect(data.get(),
 					&IPU3CameraData::imguOutputBufferReady);
 		data->imgu_->viewfinder_.dev->bufferReady.connect(data.get(),
@@ -916,22 +914,6 @@ int PipelineHandlerIPU3::registerCameras()
  */
 
 /**
- * \brief Handle buffers completion at the ImgU input
- * \param[in] buffer The completed buffer
- *
- * Buffers completed from the ImgU input are immediately queued back to the
- * CIO2 unit to continue frame capture.
- */
-void IPU3CameraData::imguInputBufferReady(FrameBuffer *buffer)
-{
-	/* \todo Handle buffer failures when state is set to BufferError. */
-	if (buffer->metadata().status == FrameMetadata::FrameCancelled)
-		return;
-
-	cio2_.putBuffer(buffer);
-}
-
-/**
  * \brief Handle buffers completion at the ImgU output
  * \param[in] buffer The completed buffer
  *
@@ -963,27 +945,18 @@ void IPU3CameraData::cio2BufferReady(FrameBuffer *buffer)
 		return;
 
 	Request *request = buffer->request();
-	FrameBuffer *raw = request->findBuffer(&rawStream_);
 
-	if (!raw) {
-		/* No RAW buffers present, just queue to IMGU. */
-		imgu_->input_->queueBuffer(buffer);
+	/*
+	 * 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_) &&
+	    pipe_->completeBuffer(camera_, request, buffer)) {
+		pipe_->completeRequest(camera_, request);
 		return;
 	}
 
-	/* RAW buffers present, special care is needed. */
-	if (request->buffers().size() > 1)
-		imgu_->input_->queueBuffer(buffer);
-
-	if (raw->copyFrom(buffer))
-		LOG(IPU3, Debug) << "Copy of FrameBuffer failed";
-
-	pipe_->completeBuffer(camera_, request, raw);
-
-	if (request->buffers().size() == 1) {
-		cio2_.putBuffer(buffer);
-		pipe_->completeRequest(camera_, request);
-	}
+	imgu_->input_->queueBuffer(buffer);
 }
 
 /* -----------------------------------------------------------------------------