[PATCH v2 2/2] ipa: rkisp1: Have algos initialize FrameContext

[Jacopo Mondi]

The RkISP1 AGC algorithms assumes the metering mode to be
"MeteringMatrix" and pre-fill an array of weights associated
with it stored in meteringModes_[MeteringMatrix] when intializing
the algorithm in parseMeteringModes().

It laters fetches the weights when computing parameters using the
FrameContext.agc.meteringMode as index of the meteringModes_ array.

When a Request gets queued to the algorithm, the
FrameContext.agc.meteringMode index is populated from the algorithm's
active state, and optionally updated if the application has specified
a different metering mode.

In case of Request underrun however, a non-initialized FrameContext
gets provided to the algorithm, causing an (unhandled) exception when
accessing the meteringModes_ array.

To handle the situation when a Request underrun occours and let
algorithms initialize a FrameContext to safe defaults:

- Add an 'underrun' flag to FrameContext
- Add an 'initFrameContext()' function to RkISP1 algorithms
- If a FrameContext is get() before being allocated, pass it through
  the algorithms' initFrameContext() to safely initialize it

Signed-off-by: Jacopo Mondi <jacopo.mondi at ideasonboard.com>
---
 src/ipa/libipa/fc_queue.cpp           | 6 ++++++
 src/ipa/libipa/fc_queue.h             | 5 +++++
 src/ipa/rkisp1/algorithms/agc.cpp     | 8 ++++++++
 src/ipa/rkisp1/algorithms/agc.h       | 4 ++++
 src/ipa/rkisp1/algorithms/algorithm.h | 5 +++++
 src/ipa/rkisp1/rkisp1.cpp             | 9 +++++++++
 6 files changed, 37 insertions(+)

diff --git a/src/ipa/libipa/fc_queue.cpp b/src/ipa/libipa/fc_queue.cpp
index 0365e9197748..44f9d866ad1b 100644
--- a/src/ipa/libipa/fc_queue.cpp
+++ b/src/ipa/libipa/fc_queue.cpp
@@ -36,6 +36,12 @@ namespace ipa {
  *
  * \var FrameContext::frame
  * \brief The frame number
+ *
+ * \var FrameContext::underrun
+ * \brief Boolean flag that reports if the FrameContext has been accessed with
+ * a FCQeueu::get() call before being FCQueue::alloc()-ated. If the flag is set
+ * to True then the frame context needs to be initialized by algorithms to safe
+ * defaults as it won't be initialized with any non-user provided control.
  */
 
 /**
diff --git a/src/ipa/libipa/fc_queue.h b/src/ipa/libipa/fc_queue.h
index a1d136521107..d70ca9601bd7 100644
--- a/src/ipa/libipa/fc_queue.h
+++ b/src/ipa/libipa/fc_queue.h
@@ -22,6 +22,9 @@ template<typename FrameContext>
 class FCQueue;
 
 struct FrameContext {
+public:
+	bool underrun = false;
+
 private:
 	template<typename T> friend class FCQueue;
 	uint32_t frame;
@@ -97,6 +100,7 @@ public:
 			 * is called before alloc() by the IPA for frame#0.
 			 */
 			init(frameContext, frame);
+			frameContext.underrun = true;
 
 			return frameContext;
 		}
@@ -117,6 +121,7 @@ public:
 			<< "Obtained an uninitialised FrameContext for " << frame;
 
 		init(frameContext, frame);
+		frameContext.underrun = true;
 
 		return frameContext;
 	}
diff --git a/src/ipa/rkisp1/algorithms/agc.cpp b/src/ipa/rkisp1/algorithms/agc.cpp
index 301b7ec26508..4122f665b3ee 100644
--- a/src/ipa/rkisp1/algorithms/agc.cpp
+++ b/src/ipa/rkisp1/algorithms/agc.cpp
@@ -204,6 +204,14 @@ int Agc::configure(IPAContext &context, const IPACameraSensorInfo &configInfo)
 	return 0;
 }
 
+void Agc::initFrameContext(IPAContext &context,
+			   IPAFrameContext &frameContext)
+{
+	auto &agc = context.activeState.agc;
+
+	frameContext.agc.meteringMode = agc.meteringMode;
+}
+
 /**
  * \copydoc libcamera::ipa::Algorithm::queueRequest
  */
diff --git a/src/ipa/rkisp1/algorithms/agc.h b/src/ipa/rkisp1/algorithms/agc.h
index aa86f2c5bc21..c1adf91bbc4e 100644
--- a/src/ipa/rkisp1/algorithms/agc.h
+++ b/src/ipa/rkisp1/algorithms/agc.h
@@ -30,6 +30,10 @@ public:
 
 	int init(IPAContext &context, const YamlObject &tuningData) override;
 	int configure(IPAContext &context, const IPACameraSensorInfo &configInfo) override;
+
+	void initFrameContext(IPAContext &context,
+			      IPAFrameContext &frameContext) override;
+
 	void queueRequest(IPAContext &context,
 			  const uint32_t frame,
 			  IPAFrameContext &frameContext,
diff --git a/src/ipa/rkisp1/algorithms/algorithm.h b/src/ipa/rkisp1/algorithms/algorithm.h
index 715cfcd8298b..82603b7b372d 100644
--- a/src/ipa/rkisp1/algorithms/algorithm.h
+++ b/src/ipa/rkisp1/algorithms/algorithm.h
@@ -23,6 +23,11 @@ public:
 	{
 	}
 
+	virtual void initFrameContext([[maybe_unused]] IPAContext &context,
+				      [[maybe_unused]] IPAFrameContext &frameContext)
+	{
+	}
+
 	bool disabled_;
 	bool supportsRaw_;
 };
diff --git a/src/ipa/rkisp1/rkisp1.cpp b/src/ipa/rkisp1/rkisp1.cpp
index 9e161cabdea4..b743de9ff6af 100644
--- a/src/ipa/rkisp1/rkisp1.cpp
+++ b/src/ipa/rkisp1/rkisp1.cpp
@@ -353,6 +353,15 @@ void IPARkISP1::processStatsBuffer(const uint32_t frame, const uint32_t bufferId
 {
 	IPAFrameContext &frameContext = context_.frameContexts.get(frame);
 
+	if (frameContext.underrun) {
+		for (auto const &a : algorithms()) {
+			Algorithm *algo = static_cast<Algorithm *>(a.get());
+			if (algo->disabled_)
+				continue;
+			algo->initFrameContext(context_, frameContext);
+		}
+	}
+
 	/*
 	 * In raw capture mode, the ISP is bypassed and no statistics buffer is
 	 * provided.
-- 
2.47.0