[libcamera-devel] [RFC PATCH 2/3] libcamera: pipeline: rkisp1: Allow bufferCount to be user-configurable

[Nícolas F. R. A. Prado]

Allow the StreamConfiguration's bufferCount to be changed by the user.
This allows the user to, after increasing bufferCount, allocate more
buffers through FrameBufferAllocator.

Signed-off-by: Nícolas F. R. A. Prado <nfraprado at collabora.com>
---
 src/libcamera/pipeline/rkisp1/rkisp1.cpp      |  4 ++--
 src/libcamera/pipeline/rkisp1/rkisp1_path.cpp | 12 +++++++-----
 src/libcamera/pipeline/rkisp1/rkisp1_path.h   |  4 ++--
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
index 549f4a4e61a8..c7b93b2804c7 100644
--- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
+++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
@@ -792,7 +792,7 @@ int PipelineHandlerRkISP1::start(Camera *camera, [[maybe_unused]] const ControlL
 	}
 
 	if (data->mainPath_->isEnabled()) {
-		ret = mainPath_.start();
+		ret = mainPath_.start(data->mainPathStream_.configuration());
 		if (ret) {
 			param_->streamOff();
 			stat_->streamOff();
@@ -803,7 +803,7 @@ int PipelineHandlerRkISP1::start(Camera *camera, [[maybe_unused]] const ControlL
 	}
 
 	if (data->selfPath_->isEnabled()) {
-		ret = selfPath_.start();
+		ret = selfPath_.start(data->selfPathStream_.configuration());
 		if (ret) {
 			mainPath_.stop();
 			param_->streamOff();
diff --git a/src/libcamera/pipeline/rkisp1/rkisp1_path.cpp b/src/libcamera/pipeline/rkisp1/rkisp1_path.cpp
index 25f482eb8d8e..a03b5c23b87e 100644
--- a/src/libcamera/pipeline/rkisp1/rkisp1_path.cpp
+++ b/src/libcamera/pipeline/rkisp1/rkisp1_path.cpp
@@ -61,7 +61,7 @@ StreamConfiguration RkISP1Path::generateConfiguration(const Size &resolution)
 	StreamConfiguration cfg(formats);
 	cfg.pixelFormat = formats::NV12;
 	cfg.size = maxResolution;
-	cfg.bufferCount = RKISP1_BUFFER_COUNT;
+	cfg.bufferCount = RKISP1_MIN_BUFFER_COUNT;
 
 	return cfg;
 }
@@ -77,7 +77,10 @@ CameraConfiguration::Status RkISP1Path::validate(StreamConfiguration *cfg)
 
 	cfg->size.boundTo(maxResolution_);
 	cfg->size.expandTo(minResolution_);
-	cfg->bufferCount = RKISP1_BUFFER_COUNT;
+	if (cfg->bufferCount < RKISP1_MIN_BUFFER_COUNT) {
+		cfg->bufferCount = RKISP1_MIN_BUFFER_COUNT;
+		status = CameraConfiguration::Adjusted;
+	}
 
 	V4L2DeviceFormat format;
 	format.fourcc = video_->toV4L2PixelFormat(cfg->pixelFormat);
@@ -164,15 +167,14 @@ int RkISP1Path::configure(const StreamConfiguration &config,
 	return 0;
 }
 
-int RkISP1Path::start()
+int RkISP1Path::start(const StreamConfiguration &config)
 {
 	int ret;
 
 	if (running_)
 		return -EBUSY;
 
-	/* \todo Make buffer count user configurable. */
-	ret = video_->importBuffers(RKISP1_BUFFER_COUNT);
+	ret = video_->importBuffers(config.bufferCount);
 	if (ret)
 		return ret;
 
diff --git a/src/libcamera/pipeline/rkisp1/rkisp1_path.h b/src/libcamera/pipeline/rkisp1/rkisp1_path.h
index 3b3e37d258d0..13291da89dc5 100644
--- a/src/libcamera/pipeline/rkisp1/rkisp1_path.h
+++ b/src/libcamera/pipeline/rkisp1/rkisp1_path.h
@@ -49,14 +49,14 @@ public:
 		return video_->exportBuffers(bufferCount, buffers);
 	}
 
-	int start();
+	int start(const StreamConfiguration &config);
 	void stop();
 
 	int queueBuffer(FrameBuffer *buffer) { return video_->queueBuffer(buffer); }
 	Signal<FrameBuffer *> &bufferReady() { return video_->bufferReady; }
 
 private:
-	static constexpr unsigned int RKISP1_BUFFER_COUNT = 4;
+	static constexpr unsigned int RKISP1_MIN_BUFFER_COUNT = 4;
 
 	const char *name_;
 	bool running_;
-- 
2.31.1