ipa: raspberrypi: Return an error code from Algorithm::read()

When encountering errors, the Algorithm::read() function either uses
LOG(Fatal) or throws exceptions from the boost property_tree functions.
To prepare for replacing boost JSON parse with the YamlParser class,
give the Algorithm::read() function the ability to return an error code,
and propagate it all the way to the IPA module init() function.

All algorithm classes return a hardcoded 0 value for now, subsequent
commits will change that.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Naushir Patuck <naush@raspberrypi.com>
Tested-by: Naushir Patuck <naush@raspberrypi.com>

31 files changed, 151 insertions, 75 deletions

diff --git a/src/ipa/raspberrypi/controller/algorithm.cpp b/src/ipa/raspberrypi/controller/algorithm.cpp
index 1a7d20a4..d73cb36f 100644
--- a/src/ipa/raspberrypi/controller/algorithm.cpp
+++ b/src/ipa/raspberrypi/controller/algorithm.cpp
@@ -9,8 +9,9 @@
 
 using namespace RPiController;
 
-void Algorithm::read([[maybe_unused]] boost::property_tree::ptree const &params)
+int Algorithm::read([[maybe_unused]] boost::property_tree::ptree const &params)
 {
+	return 0;
 }
 
 void Algorithm::initialise()
diff --git a/src/ipa/raspberrypi/controller/algorithm.h b/src/ipa/raspberrypi/controller/algorithm.h
index 92fd895d..0c5566fd 100644
--- a/src/ipa/raspberrypi/controller/algorithm.h
+++ b/src/ipa/raspberrypi/controller/algorithm.h
@@ -35,7 +35,7 @@ public:
 	virtual bool isPaused() const { return paused_; }
 	virtual void pause() { paused_ = true; }
 	virtual void resume() { paused_ = false; }
-	virtual void read(boost::property_tree::ptree const &params);
+	virtual int read(boost::property_tree::ptree const &params);
 	virtual void initialise();
 	virtual void switchMode(CameraMode const &cameraMode, Metadata *metadata);
 	virtual void prepare(Metadata *imageMetadata);
diff --git a/src/ipa/raspberrypi/controller/controller.cpp b/src/ipa/raspberrypi/controller/controller.cpp
index 872a3230..d91ac907 100644
--- a/src/ipa/raspberrypi/controller/controller.cpp
+++ b/src/ipa/raspberrypi/controller/controller.cpp
@@ -32,19 +32,23 @@ Controller::Controller(char const *jsonFilename)
 
 Controller::~Controller() {}
 
-void Controller::read(char const *filename)
+int Controller::read(char const *filename)
 {
 	boost::property_tree::ptree root;
 	boost::property_tree::read_json(filename, root);
 	for (auto const &keyAndValue : root) {
 		Algorithm *algo = createAlgorithm(keyAndValue.first.c_str());
 		if (algo) {
-			algo->read(keyAndValue.second);
+			int ret = algo->read(keyAndValue.second);
+			if (ret)
+				return ret;
 			algorithms_.push_back(AlgorithmPtr(algo));
 		} else
 			LOG(RPiController, Warning)
 				<< "No algorithm found for \"" << keyAndValue.first << "\"";
 	}
+
+	return 0;
 }
 
 Algorithm *Controller::createAlgorithm(char const *name)
diff --git a/src/ipa/raspberrypi/controller/controller.h b/src/ipa/raspberrypi/controller/controller.h
index e28e30d7..841783bb 100644
--- a/src/ipa/raspberrypi/controller/controller.h
+++ b/src/ipa/raspberrypi/controller/controller.h
@@ -41,7 +41,7 @@ public:
 	Controller(char const *jsonFilename);
 	~Controller();
 	Algorithm *createAlgorithm(char const *name);
-	void read(char const *filename);
+	int read(char const *filename);
 	void initialise();
 	void switchMode(CameraMode const &cameraMode, Metadata *metadata);
 	void prepare(Metadata *imageMetadata);
diff --git a/src/ipa/raspberrypi/controller/pwl.cpp b/src/ipa/raspberrypi/controller/pwl.cpp
index 8b8db722..fde0b298 100644
--- a/src/ipa/raspberrypi/controller/pwl.cpp
+++ b/src/ipa/raspberrypi/controller/pwl.cpp
@@ -12,7 +12,7 @@
 
 using namespace RPiController;
 
-void Pwl::read(boost::property_tree::ptree const &params)
+int Pwl::read(boost::property_tree::ptree const &params)
 {
 	for (auto it = params.begin(); it != params.end(); it++) {
 		double x = it->second.get_value<double>();
@@ -22,6 +22,7 @@ void Pwl::read(boost::property_tree::ptree const &params)
 		points_.push_back(Point(x, y));
 	}
 	assert(points_.size() >= 2);
+	return 0;
 }
 
 void Pwl::append(double x, double y, const double eps)
diff --git a/src/ipa/raspberrypi/controller/pwl.h b/src/ipa/raspberrypi/controller/pwl.h
index 973efdf5..ef1cc2ed 100644
--- a/src/ipa/raspberrypi/controller/pwl.h
+++ b/src/ipa/raspberrypi/controller/pwl.h
@@ -57,7 +57,7 @@ public:
 	};
 	Pwl() {}
 	Pwl(std::vector<Point> const &points) : points_(points) {}
-	void read(boost::property_tree::ptree const &params);
+	int read(boost::property_tree::ptree const &params);
 	void append(double x, double y, const double eps = 1e-6);
 	void prepend(double x, double y, const double eps = 1e-6);
 	Interval domain() const;
diff --git a/src/ipa/raspberrypi/controller/rpi/agc.cpp b/src/ipa/raspberrypi/controller/rpi/agc.cpp
index 4d916cd3..7d3e1b18 100644
--- a/src/ipa/raspberrypi/controller/rpi/agc.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/agc.cpp
@@ -30,7 +30,7 @@ LOG_DEFINE_CATEGORY(RPiAgc)
 
 static constexpr unsigned int PipelineBits = 13; /* seems to be a 13-bit pipeline */
 
-void AgcMeteringMode::read(boost::property_tree::ptree const &params)
+int AgcMeteringMode::read(boost::property_tree::ptree const &params)
 {
 	int num = 0;
 	for (auto &p : params.get_child("weights")) {
@@ -40,6 +40,7 @@ void AgcMeteringMode::read(boost::property_tree::ptree const &params)
 	}
 	if (num != AgcStatsSize)
 		LOG(RPiAgc, Fatal) << "AgcMeteringMode: insufficient weights";
+	return 0;
 }
 
 static std::string
@@ -73,7 +74,7 @@ static int readList(std::vector<Duration> &list,
 	return list.size();
 }
 
-void AgcExposureMode::read(boost::property_tree::ptree const &params)
+int AgcExposureMode::read(boost::property_tree::ptree const &params)
 {
 	int numShutters = readList(shutter, params.get_child("shutter"));
 	int numAgs = readList(gain, params.get_child("gain"));
@@ -83,6 +84,7 @@ void AgcExposureMode::read(boost::property_tree::ptree const &params)
 	if (numShutters != numAgs)
 		LOG(RPiAgc, Fatal)
 			<< "AgcExposureMode: expect same number of exposure and gain entries in exposure profile";
+	return 0;
 }
 
 static std::string
@@ -100,7 +102,7 @@ readExposureModes(std::map<std::string, AgcExposureMode> &exposureModes,
 	return first;
 }
 
-void AgcConstraint::read(boost::property_tree::ptree const &params)
+int AgcConstraint::read(boost::property_tree::ptree const &params)
 {
 	std::string boundString = params.get<std::string>("bound", "");
 	transform(boundString.begin(), boundString.end(),
@@ -110,7 +112,7 @@ void AgcConstraint::read(boost::property_tree::ptree const &params)
 	bound = boundString == "UPPER" ? Bound::UPPER : Bound::LOWER;
 	qLo = params.get<double>("q_lo");
 	qHi = params.get<double>("q_hi");
-	yTarget.read(params.get_child("y_target"));
+	return yTarget.read(params.get_child("y_target"));
 }
 
 static AgcConstraintMode
@@ -137,13 +139,17 @@ static std::string readConstraintModes(std::map<std::string, AgcConstraintMode>
 	return first;
 }
 
-void AgcConfig::read(boost::property_tree::ptree const &params)
+int AgcConfig::read(boost::property_tree::ptree const &params)
 {
 	LOG(RPiAgc, Debug) << "AgcConfig";
 	defaultMeteringMode = readMeteringModes(meteringModes, params.get_child("metering_modes"));
 	defaultExposureMode = readExposureModes(exposureModes, params.get_child("exposure_modes"));
 	defaultConstraintMode = readConstraintModes(constraintModes, params.get_child("constraint_modes"));
-	yTarget.read(params.get_child("y_target"));
+
+	int ret = yTarget.read(params.get_child("y_target"));
+	if (ret)
+		return ret;
+
 	speed = params.get<double>("speed", 0.2);
 	startupFrames = params.get<uint16_t>("startup_frames", 10);
 	convergenceFrames = params.get<unsigned int>("convergence_frames", 6);
@@ -152,6 +158,7 @@ void AgcConfig::read(boost::property_tree::ptree const &params)
 	/* Start with quite a low value as ramping up is easier than ramping down. */
 	defaultExposureTime = params.get<double>("default_exposure_time", 1000) * 1us;
 	defaultAnalogueGain = params.get<double>("default_analogueGain", 1.0);
+	return 0;
 }
 
 Agc::ExposureValues::ExposureValues()
@@ -182,10 +189,14 @@ char const *Agc::name() const
 	return NAME;
 }
 
-void Agc::read(boost::property_tree::ptree const &params)
+int Agc::read(boost::property_tree::ptree const &params)
 {
 	LOG(RPiAgc, Debug) << "Agc";
-	config_.read(params);
+
+	int ret = config_.read(params);
+	if (ret)
+		return ret;
+
 	/*
 	 * Set the config's defaults (which are the first ones it read) as our
 	 * current modes, until someone changes them.  (they're all known to
@@ -200,6 +211,7 @@ void Agc::read(boost::property_tree::ptree const &params)
 	/* Set up the "last shutter/gain" values, in case AGC starts "disabled". */
 	status_.shutterTime = config_.defaultExposureTime;
 	status_.analogueGain = config_.defaultAnalogueGain;
+	return 0;
 }
 
 bool Agc::isPaused() const
diff --git a/src/ipa/raspberrypi/controller/rpi/agc.h b/src/ipa/raspberrypi/controller/rpi/agc.h
index f57afa6d..1351b0ee 100644
--- a/src/ipa/raspberrypi/controller/rpi/agc.h
+++ b/src/ipa/raspberrypi/controller/rpi/agc.h
@@ -28,13 +28,13 @@ namespace RPiController {
 
 struct AgcMeteringMode {
 	double weights[AgcStatsSize];
-	void read(boost::property_tree::ptree const &params);
+	int read(boost::property_tree::ptree const &params);
 };
 
 struct AgcExposureMode {
 	std::vector<libcamera::utils::Duration> shutter;
 	std::vector<double> gain;
-	void read(boost::property_tree::ptree const &params);
+	int read(boost::property_tree::ptree const &params);
 };
 
 struct AgcConstraint {
@@ -43,13 +43,13 @@ struct AgcConstraint {
 	double qLo;
 	double qHi;
 	Pwl yTarget;
-	void read(boost::property_tree::ptree const &params);
+	int read(boost::property_tree::ptree const &params);
 };
 
 typedef std::vector<AgcConstraint> AgcConstraintMode;
 
 struct AgcConfig {
-	void read(boost::property_tree::ptree const &params);
+	int read(boost::property_tree::ptree const &params);
 	std::map<std::string, AgcMeteringMode> meteringModes;
 	std::map<std::string, AgcExposureMode> exposureModes;
 	std::map<std::string, AgcConstraintMode> constraintModes;
@@ -74,7 +74,7 @@ class Agc : public AgcAlgorithm
 public:
 	Agc(Controller *controller);
 	char const *name() const override;
-	void read(boost::property_tree::ptree const &params) override;
+	int read(boost::property_tree::ptree const &params) override;
 	/* AGC handles "pausing" for itself. */
 	bool isPaused() const override;
 	void pause() override;
diff --git a/src/ipa/raspberrypi/controller/rpi/alsc.cpp b/src/ipa/raspberrypi/controller/rpi/alsc.cpp
index 03ae3350..b3627769 100644
--- a/src/ipa/raspberrypi/controller/rpi/alsc.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/alsc.cpp
@@ -50,7 +50,7 @@ char const *Alsc::name() const
 	return NAME;
 }
 
-static void generateLut(double *lut, boost::property_tree::ptree const &params)
+static int generateLut(double *lut, boost::property_tree::ptree const &params)
 {
 	double cstrength = params.get<double>("corner_strength", 2.0);
 	if (cstrength <= 1.0)
@@ -71,9 +71,10 @@ static void generateLut(double *lut, boost::property_tree::ptree const &params)
 				(f2 * f2); /* this reproduces the cos^4 rule */
 		}
 	}
+	return 0;
 }
 
-static void readLut(double *lut, boost::property_tree::ptree const &params)
+static int readLut(double *lut, boost::property_tree::ptree const &params)
 {
 	int num = 0;
 	const int maxNum = XY;
@@ -84,11 +85,12 @@ static void readLut(double *lut, boost::property_tree::ptree const &params)
 	}
 	if (num < maxNum)
 		LOG(RPiAlsc, Fatal) << "Alsc: too few entries in LSC table";
+	return 0;
 }
 
-static void readCalibrations(std::vector<AlscCalibration> &calibrations,
-			     boost::property_tree::ptree const &params,
-			     std::string const &name)
+static int readCalibrations(std::vector<AlscCalibration> &calibrations,
+			    boost::property_tree::ptree const &params,
+			    std::string const &name)
 {
 	if (params.get_child_optional(name)) {
 		double lastCt = 0;
@@ -117,9 +119,10 @@ static void readCalibrations(std::vector<AlscCalibration> &calibrations,
 				<< "Read " << name << " calibration for ct " << ct;
 		}
 	}
+	return 0;
 }
 
-void Alsc::read(boost::property_tree::ptree const &params)
+int Alsc::read(boost::property_tree::ptree const &params)
 {
 	config_.framePeriod = params.get<uint16_t>("frame_period", 12);
 	config_.startupFrames = params.get<uint16_t>("startup_frames", 10);
@@ -135,19 +138,32 @@ void Alsc::read(boost::property_tree::ptree const &params)
 		params.get<double>("luminance_strength", 1.0);
 	for (int i = 0; i < XY; i++)
 		config_.luminanceLut[i] = 1.0;
+
+	int ret = 0;
+
 	if (params.get_child_optional("corner_strength"))
-		generateLut(config_.luminanceLut, params);
+		ret = generateLut(config_.luminanceLut, params);
 	else if (params.get_child_optional("luminance_lut"))
-		readLut(config_.luminanceLut,
-			params.get_child("luminance_lut"));
+		ret = readLut(config_.luminanceLut,
+			      params.get_child("luminance_lut"));
 	else
 		LOG(RPiAlsc, Warning)
 			<< "no luminance table - assume unity everywhere";
-	readCalibrations(config_.calibrationsCr, params, "calibrations_Cr");
-	readCalibrations(config_.calibrationsCb, params, "calibrations_Cb");
+	if (ret)
+		return ret;
+
+	ret = readCalibrations(config_.calibrationsCr, params, "calibrations_Cr");
+	if (ret)
+		return ret;
+	ret = readCalibrations(config_.calibrationsCb, params, "calibrations_Cb");
+	if (ret)
+		return ret;
+
 	config_.defaultCt = params.get<double>("default_ct", 4500.0);
 	config_.threshold = params.get<double>("threshold", 1e-3);
 	config_.lambdaBound = params.get<double>("lambda_bound", 0.05);
+
+	return 0;
 }
 
 static double getCt(Metadata *metadata, double defaultCt);
diff --git a/src/ipa/raspberrypi/controller/rpi/alsc.h b/src/ipa/raspberrypi/controller/rpi/alsc.h
index 4e9a715a..773fd338 100644
--- a/src/ipa/raspberrypi/controller/rpi/alsc.h
+++ b/src/ipa/raspberrypi/controller/rpi/alsc.h
@@ -52,7 +52,7 @@ public:
 	char const *name() const override;
 	void initialise() override;
 	void switchMode(CameraMode const &cameraMode, Metadata *metadata) override;
-	void read(boost::property_tree::ptree const &params) override;
+	int read(boost::property_tree::ptree const &params) override;
 	void prepare(Metadata *imageMetadata) override;
 	void process(StatisticsPtr &stats, Metadata *imageMetadata) override;
 
diff --git a/src/ipa/raspberrypi/controller/rpi/awb.cpp b/src/ipa/raspberrypi/controller/rpi/awb.cpp
index 6c2b627d..cd97d9f4 100644
--- a/src/ipa/raspberrypi/controller/rpi/awb.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/awb.cpp
@@ -26,20 +26,21 @@ static constexpr unsigned int AwbStatsSizeY = DEFAULT_AWB_REGIONS_Y;
  * elsewhere (ALSC and AGC).
  */
 
-void AwbMode::read(boost::property_tree::ptree const &params)
+int AwbMode::read(boost::property_tree::ptree const &params)
 {
 	ctLo = params.get<double>("lo");
 	ctHi = params.get<double>("hi");
+	return 0;
 }
 
-void AwbPrior::read(boost::property_tree::ptree const &params)
+int AwbPrior::read(boost::property_tree::ptree const &params)
 {
 	lux = params.get<double>("lux");
-	prior.read(params.get_child("prior"));
+	return prior.read(params.get_child("prior"));
 }
 
-static void readCtCurve(Pwl &ctR, Pwl &ctB,
-			boost::property_tree::ptree const &params)
+static int readCtCurve(Pwl &ctR, Pwl &ctB,
+		       boost::property_tree::ptree const &params)
 {
 	int num = 0;
 	for (auto it = params.begin(); it != params.end(); it++) {
@@ -55,21 +56,28 @@ static void readCtCurve(Pwl &ctR, Pwl &ctB,
 	}
 	if (num < 2)
 		LOG(RPiAwb, Fatal) << "AwbConfig: insufficient points in CT curve";
+	return 0;
 }
 
-void AwbConfig::read(boost::property_tree::ptree const &params)
+int AwbConfig::read(boost::property_tree::ptree const &params)
 {
+	int ret;
 	bayes = params.get<int>("bayes", 1);
 	framePeriod = params.get<uint16_t>("framePeriod", 10);
 	startupFrames = params.get<uint16_t>("startupFrames", 10);
 	convergenceFrames = params.get<unsigned int>("convergence_frames", 3);
 	speed = params.get<double>("speed", 0.05);
-	if (params.get_child_optional("ct_curve"))
-		readCtCurve(ctR, ctB, params.get_child("ct_curve"));
+	if (params.get_child_optional("ct_curve")) {
+		ret = readCtCurve(ctR, ctB, params.get_child("ct_curve"));
+		if (ret)
+			return ret;
+	}
 	if (params.get_child_optional("priors")) {
 		for (auto &p : params.get_child("priors")) {
 			AwbPrior prior;
-			prior.read(p.second);
+			ret = prior.read(p.second);
+			if (ret)
+				return ret;
 			if (!priors.empty() && prior.lux <= priors.back().lux)
 				LOG(RPiAwb, Fatal) << "AwbConfig: Prior must be ordered in increasing lux value";
 			priors.push_back(prior);
@@ -79,7 +87,9 @@ void AwbConfig::read(boost::property_tree::ptree const &params)
 	}
 	if (params.get_child_optional("modes")) {
 		for (auto &p : params.get_child("modes")) {
-			modes[p.first].read(p.second);
+			ret = modes[p.first].read(p.second);
+			if (ret)
+				return ret;
 			if (defaultMode == nullptr)
 				defaultMode = &modes[p.first];
 		}
@@ -110,6 +120,7 @@ void AwbConfig::read(boost::property_tree::ptree const &params)
 	whitepointB = params.get<double>("whitepoint_b", 0.0);
 	if (bayes == false)
 		sensitivityR = sensitivityB = 1.0; /* nor do sensitivities make any sense */
+	return 0;
 }
 
 Awb::Awb(Controller *controller)
@@ -137,9 +148,9 @@ char const *Awb::name() const
 	return NAME;
 }
 
-void Awb::read(boost::property_tree::ptree const &params)
+int Awb::read(boost::property_tree::ptree const &params)
 {
-	config_.read(params);
+	return config_.read(params);
 }
 
 void Awb::initialise()
diff --git a/src/ipa/raspberrypi/controller/rpi/awb.h b/src/ipa/raspberrypi/controller/rpi/awb.h
index 61c6ea7b..9c5cf4ea 100644
--- a/src/ipa/raspberrypi/controller/rpi/awb.h
+++ b/src/ipa/raspberrypi/controller/rpi/awb.h
@@ -19,20 +19,20 @@ namespace RPiController {
 /* Control algorithm to perform AWB calculations. */
 
 struct AwbMode {
-	void read(boost::property_tree::ptree const &params);
+	int read(boost::property_tree::ptree const &params);
 	double ctLo; /* low CT value for search */
 	double ctHi; /* high CT value for search */
 };
 
 struct AwbPrior {
-	void read(boost::property_tree::ptree const &params);
+	int read(boost::property_tree::ptree const &params);
 	double lux; /* lux level */
 	Pwl prior; /* maps CT to prior log likelihood for this lux level */
 };
 
 struct AwbConfig {
 	AwbConfig() : defaultMode(nullptr) {}
-	void read(boost::property_tree::ptree const &params);
+	int read(boost::property_tree::ptree const &params);
 	/* Only repeat the AWB calculation every "this many" frames */
 	uint16_t framePeriod;
 	/* number of initial frames for which speed taken as 1.0 (maximum) */
@@ -90,7 +90,7 @@ public:
 	~Awb();
 	char const *name() const override;
 	void initialise() override;
-	void read(boost::property_tree::ptree const &params) override;
+	int read(boost::property_tree::ptree const &params) override;
 	/* AWB handles "pausing" for itself. */
 	bool isPaused() const override;
 	void pause() override;
diff --git a/src/ipa/raspberrypi/controller/rpi/black_level.cpp b/src/ipa/raspberrypi/controller/rpi/black_level.cpp
index def19ccb..749fcd7c 100644
--- a/src/ipa/raspberrypi/controller/rpi/black_level.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/black_level.cpp
@@ -31,7 +31,7 @@ char const *BlackLevel::name() const
 	return NAME;
 }
 
-void BlackLevel::read(boost::property_tree::ptree const &params)
+int BlackLevel::read(boost::property_tree::ptree const &params)
 {
 	uint16_t blackLevel = params.get<uint16_t>(
 		"black_level", 4096); /* 64 in 10 bits scaled to 16 bits */
@@ -42,6 +42,7 @@ void BlackLevel::read(boost::property_tree::ptree const &params)
 		<< " Read black levels red " << blackLevelR_
 		<< " green " << blackLevelG_
 		<< " blue " << blackLevelB_;
+	return 0;
 }
 
 void BlackLevel::prepare(Metadata *imageMetadata)
diff --git a/src/ipa/raspberrypi/controller/rpi/black_level.h b/src/ipa/raspberrypi/controller/rpi/black_level.h
index 7789f261..6ec8c4f9 100644
--- a/src/ipa/raspberrypi/controller/rpi/black_level.h
+++ b/src/ipa/raspberrypi/controller/rpi/black_level.h
@@ -18,7 +18,7 @@ class BlackLevel : public Algorithm
 public:
 	BlackLevel(Controller *controller);
 	char const *name() const override;
-	void read(boost::property_tree::ptree const &params) override;
+	int read(boost::property_tree::ptree const &params) override;
 	void prepare(Metadata *imageMetadata) override;
 
 private:
diff --git a/src/ipa/raspberrypi/controller/rpi/ccm.cpp b/src/ipa/raspberrypi/controller/rpi/ccm.cpp
index cf0c85d2..f0110d38 100644
--- a/src/ipa/raspberrypi/controller/rpi/ccm.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/ccm.cpp
@@ -39,7 +39,7 @@ Matrix::Matrix(double m0, double m1, double m2, double m3, double m4, double m5,
 	m[0][0] = m0, m[0][1] = m1, m[0][2] = m2, m[1][0] = m3, m[1][1] = m4,
 	m[1][2] = m5, m[2][0] = m6, m[2][1] = m7, m[2][2] = m8;
 }
-void Matrix::read(boost::property_tree::ptree const &params)
+int Matrix::read(boost::property_tree::ptree const &params)
 {
 	double *ptr = (double *)m;
 	int n = 0;
@@ -50,6 +50,7 @@ void Matrix::read(boost::property_tree::ptree const &params)
 	}
 	if (n < 9)
 		LOG(RPiCcm, Fatal) << "Ccm: too few values in CCM";
+	return 0;
 }
 
 Ccm::Ccm(Controller *controller)
@@ -60,21 +61,32 @@ char const *Ccm::name() const
 	return NAME;
 }
 
-void Ccm::read(boost::property_tree::ptree const &params)
+int Ccm::read(boost::property_tree::ptree const &params)
 {
-	if (params.get_child_optional("saturation"))
-		config_.saturation.read(params.get_child("saturation"));
+	int ret;
+
+	if (params.get_child_optional("saturation")) {
+		ret = config_.saturation.read(params.get_child("saturation"));
+		if (ret)
+			return ret;
+	}
+
 	for (auto &p : params.get_child("ccms")) {
 		CtCcm ctCcm;
 		ctCcm.ct = p.second.get<double>("ct");
-		ctCcm.ccm.read(p.second.get_child("ccm"));
+		ret = ctCcm.ccm.read(p.second.get_child("ccm"));
+		if (ret)
+			return ret;
 		if (!config_.ccms.empty() &&
 		    ctCcm.ct <= config_.ccms.back().ct)
 			LOG(RPiCcm, Fatal) << "Ccm: CCM not in increasing colour temperature order";
 		config_.ccms.push_back(std::move(ctCcm));
 	}
+
 	if (config_.ccms.empty())
 		LOG(RPiCcm, Fatal) << "Ccm: no CCMs specified";
+
+	return 0;
 }
 
 void Ccm::setSaturation(double saturation)
diff --git a/src/ipa/raspberrypi/controller/rpi/ccm.h b/src/ipa/raspberrypi/controller/rpi/ccm.h
index b44f1576..6b65c7ae 100644
--- a/src/ipa/raspberrypi/controller/rpi/ccm.h
+++ b/src/ipa/raspberrypi/controller/rpi/ccm.h
@@ -20,7 +20,7 @@ struct Matrix {
 	       double m6, double m7, double m8);
 	Matrix();
 	double m[3][3];
-	void read(boost::property_tree::ptree const &params);
+	int read(boost::property_tree::ptree const &params);
 };
 static inline Matrix operator*(double d, Matrix const &m)
 {
@@ -62,7 +62,7 @@ class Ccm : public CcmAlgorithm
 public:
 	Ccm(Controller *controller = NULL);
 	char const *name() const override;
-	void read(boost::property_tree::ptree const &params) override;
+	int read(boost::property_tree::ptree const &params) override;
 	void setSaturation(double saturation) override;
 	void initialise() override;
 	void prepare(Metadata *imageMetadata) override;
diff --git a/src/ipa/raspberrypi/controller/rpi/contrast.cpp b/src/ipa/raspberrypi/controller/rpi/contrast.cpp
index 9e60dc5d..d76dc43b 100644
--- a/src/ipa/raspberrypi/controller/rpi/contrast.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/contrast.cpp
@@ -38,7 +38,7 @@ char const *Contrast::name() const
 	return NAME;
 }
 
-void Contrast::read(boost::property_tree::ptree const &params)
+int Contrast::read(boost::property_tree::ptree const &params)
 {
 	/* enable adaptive enhancement by default */
 	config_.ceEnable = params.get<int>("ce_enable", 1);
@@ -52,7 +52,7 @@ void Contrast::read(boost::property_tree::ptree const &params)
 	config_.hiHistogram = params.get<double>("hi_histogram", 0.95);
 	config_.hiLevel = params.get<double>("hi_level", 0.95);
 	config_.hiMax = params.get<double>("hi_max", 2000);
-	config_.gammaCurve.read(params.get_child("gamma_curve"));
+	return config_.gammaCurve.read(params.get_child("gamma_curve"));
 }
 
 void Contrast::setBrightness(double brightness)
diff --git a/src/ipa/raspberrypi/controller/rpi/contrast.h b/src/ipa/raspberrypi/controller/rpi/contrast.h
index b1375d81..5c3d2f56 100644
--- a/src/ipa/raspberrypi/controller/rpi/contrast.h
+++ b/src/ipa/raspberrypi/controller/rpi/contrast.h
@@ -34,7 +34,7 @@ class Contrast : public ContrastAlgorithm
 public:
 	Contrast(Controller *controller = NULL);
 	char const *name() const override;
-	void read(boost::property_tree::ptree const &params) override;
+	int read(boost::property_tree::ptree const &params) override;
 	void setBrightness(double brightness) override;
 	void setContrast(double contrast) override;
 	void initialise() override;
diff --git a/src/ipa/raspberrypi/controller/rpi/dpc.cpp b/src/ipa/raspberrypi/controller/rpi/dpc.cpp
index d5d784e7..be014a05 100644
--- a/src/ipa/raspberrypi/controller/rpi/dpc.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/dpc.cpp
@@ -31,11 +31,12 @@ char const *Dpc::name() const
 	return NAME;
 }
 
-void Dpc::read(boost::property_tree::ptree const &params)
+int Dpc::read(boost::property_tree::ptree const &params)
 {
 	config_.strength = params.get<int>("strength", 1);
 	if (config_.strength < 0 || config_.strength > 2)
 		LOG(RPiDpc, Fatal) << "Dpc: bad strength value";
+	return 0;
 }
 
 void Dpc::prepare(Metadata *imageMetadata)
diff --git a/src/ipa/raspberrypi/controller/rpi/dpc.h b/src/ipa/raspberrypi/controller/rpi/dpc.h
index 4c1bdec6..2bb6cef5 100644
--- a/src/ipa/raspberrypi/controller/rpi/dpc.h
+++ b/src/ipa/raspberrypi/controller/rpi/dpc.h
@@ -22,7 +22,7 @@ class Dpc : public Algorithm
 public:
 	Dpc(Controller *controller);
 	char const *name() const override;
-	void read(boost::property_tree::ptree const &params) override;
+	int read(boost::property_tree::ptree const &params) override;
 	void prepare(Metadata *imageMetadata) override;
 
 private:
diff --git a/src/ipa/raspberrypi/controller/rpi/geq.cpp b/src/ipa/raspberrypi/controller/rpi/geq.cpp
index 696da4ae..a7444787 100644
--- a/src/ipa/raspberrypi/controller/rpi/geq.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/geq.cpp
@@ -35,14 +35,20 @@ char const *Geq::name() const
 	return NAME;
 }
 
-void Geq::read(boost::property_tree::ptree const &params)
+int Geq::read(boost::property_tree::ptree const &params)
 {
 	config_.offset = params.get<uint16_t>("offset", 0);
 	config_.slope = params.get<double>("slope", 0.0);
 	if (config_.slope < 0.0 || config_.slope >= 1.0)
 		LOG(RPiGeq, Fatal) << "Geq: bad slope value";
-	if (params.get_child_optional("strength"))
-		config_.strength.read(params.get_child("strength"));
+
+	if (params.get_child_optional("strength")) {
+		int ret = config_.strength.read(params.get_child("strength"));
+		if (ret)
+			return ret;
+	}
+
+	return 0;
 }
 
 void Geq::prepare(Metadata *imageMetadata)
diff --git a/src/ipa/raspberrypi/controller/rpi/geq.h b/src/ipa/raspberrypi/controller/rpi/geq.h
index 5d06b9cb..677a0510 100644
--- a/src/ipa/raspberrypi/controller/rpi/geq.h
+++ b/src/ipa/raspberrypi/controller/rpi/geq.h
@@ -24,7 +24,7 @@ class Geq : public Algorithm
 public:
 	Geq(Controller *controller);
 	char const *name() const override;
-	void read(boost::property_tree::ptree const &params) override;
+	int read(boost::property_tree::ptree const &params) override;
 	void prepare(Metadata *imageMetadata) override;
 
 private:
diff --git a/src/ipa/raspberrypi/controller/rpi/lux.cpp b/src/ipa/raspberrypi/controller/rpi/lux.cpp
index 95c0a93b..ca1e8271 100644
--- a/src/ipa/raspberrypi/controller/rpi/lux.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/lux.cpp
@@ -38,7 +38,7 @@ char const *Lux::name() const
 	return NAME;
 }
 
-void Lux::read(boost::property_tree::ptree const &params)
+int Lux::read(boost::property_tree::ptree const &params)
 {
 	referenceShutterSpeed_ =
 		params.get<double>("reference_shutter_speed") * 1.0us;
@@ -47,6 +47,7 @@ void Lux::read(boost::property_tree::ptree const &params)
 	referenceY_ = params.get<double>("reference_Y");
 	referenceLux_ = params.get<double>("reference_lux");
 	currentAperture_ = referenceAperture_;
+	return 0;
 }
 
 void Lux::setCurrentAperture(double aperture)
diff --git a/src/ipa/raspberrypi/controller/rpi/lux.h b/src/ipa/raspberrypi/controller/rpi/lux.h
index 26af8185..6416dfb5 100644
--- a/src/ipa/raspberrypi/controller/rpi/lux.h
+++ b/src/ipa/raspberrypi/controller/rpi/lux.h
@@ -22,7 +22,7 @@ class Lux : public Algorithm
 public:
 	Lux(Controller *controller);
 	char const *name() const override;
-	void read(boost::property_tree::ptree const &params) override;
+	int read(boost::property_tree::ptree const &params) override;
 	void prepare(Metadata *imageMetadata) override;
 	void process(StatisticsPtr &stats, Metadata *imageMetadata) override;
 	void setCurrentAperture(double aperture);
diff --git a/src/ipa/raspberrypi/controller/rpi/noise.cpp b/src/ipa/raspberrypi/controller/rpi/noise.cpp
index 5d2c85ad..74fa99ba 100644
--- a/src/ipa/raspberrypi/controller/rpi/noise.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/noise.cpp
@@ -41,10 +41,11 @@ void Noise::switchMode(CameraMode const &cameraMode,
 	modeFactor_ = std::max(1.0, cameraMode.noiseFactor);
 }
 
-void Noise::read(boost::property_tree::ptree const &params)
+int Noise::read(boost::property_tree::ptree const &params)
 {
 	referenceConstant_ = params.get<double>("reference_constant");
 	referenceSlope_ = params.get<double>("reference_slope");
+	return 0;
 }
 
 void Noise::prepare(Metadata *imageMetadata)
diff --git a/src/ipa/raspberrypi/controller/rpi/noise.h b/src/ipa/raspberrypi/controller/rpi/noise.h
index 144e3652..b33a5fc7 100644
--- a/src/ipa/raspberrypi/controller/rpi/noise.h
+++ b/src/ipa/raspberrypi/controller/rpi/noise.h
@@ -19,7 +19,7 @@ public:
 	Noise(Controller *controller);
 	char const *name() const override;
 	void switchMode(CameraMode const &cameraMode, Metadata *metadata) override;
-	void read(boost::property_tree::ptree const &params) override;
+	int read(boost::property_tree::ptree const &params) override;
 	void prepare(Metadata *imageMetadata) override;
 
 private:
diff --git a/src/ipa/raspberrypi/controller/rpi/sdn.cpp b/src/ipa/raspberrypi/controller/rpi/sdn.cpp
index af31bd08..03d9f119 100644
--- a/src/ipa/raspberrypi/controller/rpi/sdn.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/sdn.cpp
@@ -34,10 +34,11 @@ char const *Sdn::name() const
 	return NAME;
 }
 
-void Sdn::read(boost::property_tree::ptree const &params)
+int Sdn::read(boost::property_tree::ptree const &params)
 {
 	deviation_ = params.get<double>("deviation", 3.2);
 	strength_ = params.get<double>("strength", 0.75);
+	return 0;
 }
 
 void Sdn::initialise()
diff --git a/src/ipa/raspberrypi/controller/rpi/sdn.h b/src/ipa/raspberrypi/controller/rpi/sdn.h
index 90ea37ff..4287ef08 100644
--- a/src/ipa/raspberrypi/controller/rpi/sdn.h
+++ b/src/ipa/raspberrypi/controller/rpi/sdn.h
@@ -18,7 +18,7 @@ class Sdn : public DenoiseAlgorithm
 public:
 	Sdn(Controller *controller = NULL);
 	char const *name() const override;
-	void read(boost::property_tree::ptree const &params) override;
+	int read(boost::property_tree::ptree const &params) override;
 	void initialise() override;
 	void prepare(Metadata *imageMetadata) override;
 	void setMode(DenoiseMode mode) override;
diff --git a/src/ipa/raspberrypi/controller/rpi/sharpen.cpp b/src/ipa/raspberrypi/controller/rpi/sharpen.cpp
index 36b75f69..9c4cffa4 100644
--- a/src/ipa/raspberrypi/controller/rpi/sharpen.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/sharpen.cpp
@@ -37,7 +37,7 @@ void Sharpen::switchMode(CameraMode const &cameraMode,
 	modeFactor_ = std::max(1.0, cameraMode.noiseFactor);
 }
 
-void Sharpen::read(boost::property_tree::ptree const &params)
+int Sharpen::read(boost::property_tree::ptree const &params)
 {
 	threshold_ = params.get<double>("threshold", 1.0);
 	strength_ = params.get<double>("strength", 1.0);
@@ -46,6 +46,7 @@ void Sharpen::read(boost::property_tree::ptree const &params)
 		<< "Read threshold " << threshold_
 		<< " strength " << strength_
 		<< " limit " << limit_;
+	return 0;
 }
 
 void Sharpen::setStrength(double strength)
diff --git a/src/ipa/raspberrypi/controller/rpi/sharpen.h b/src/ipa/raspberrypi/controller/rpi/sharpen.h
index 8846f2ae..0cd8b92f 100644
--- a/src/ipa/raspberrypi/controller/rpi/sharpen.h
+++ b/src/ipa/raspberrypi/controller/rpi/sharpen.h
@@ -19,7 +19,7 @@ public:
 	Sharpen(Controller *controller);
 	char const *name() const override;
 	void switchMode(CameraMode const &cameraMode, Metadata *metadata) override;
-	void read(boost::property_tree::ptree const &params) override;
+	int read(boost::property_tree::ptree const &params) override;
 	void setStrength(double strength) override;
 	void prepare(Metadata *imageMetadata) override;
 
diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
index 9d550354..b9e9b814 100644
--- a/src/ipa/raspberrypi/raspberrypi.cpp
+++ b/src/ipa/raspberrypi/raspberrypi.cpp
@@ -229,7 +229,14 @@ int IPARPi::init(const IPASettings &settings, IPAInitResult *result)
 	result->sensorConfig.sensorMetadata = sensorMetadata;
 
 	/* Load the tuning file for this sensor. */
-	controller_.read(settings.configurationFile.c_str());
+	int ret = controller_.read(settings.configurationFile.c_str());
+	if (ret) {
+		LOG(IPARPI, Error)
+			<< "Failed to load tuning data file "
+			<< settings.configurationFile;
+		return ret;
+	}
+
 	controller_.initialise();
 
 	/* Return the controls handled by the IPA */