libcamera: control_serializer: Add array info to serialized ControlValue

Array controls (eg. ColourCorrectionMatrix, FrameDurationLimits,
ColourGains) are serialized properly by the ControlSerializer, but are
not deserialized properly. This is because their arrayness and size are
not considered during deserialization.

Fix this by adding arrayness and size to the serialized form of all
ControlValues. This is achieved by fully serializing the min/max/def
ControlValue's metadata associated with each ControlInfo entry in the
ControlInfoMap.

While at it, clean up the serialization format of ControlValues and
ControlLists:
- ControlValue's id is only used by ControlList, so add a new struct for
  ControlList entries to contain it, and remove id from ControlValue
- Remove offset from ControlInfo's entry, as it is no longer needed,
  since the serialized data of a ControlInfo has now been converted to
  simply three serialized ControlValues
- Remove the type from the serialized data of ControlValue, as it is
  already in the metadata entry

The issue regarding array controls was not noticed before because the
default value of the ControlInfo of other array controls had been set to
scalar values similar to how min/max are set, and ColourCorrectionMatrix
was the first control to properly define a non-scalar default value.

Bug: https://bugs.libcamera.org/show_bug.cgi?id=285
Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Tested-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com> # rkisp1

Author: Rahi374

include/libcamera/internal/control_serializer.h

@@ -47,9 +47,13 @@ class ControlSerializer
 	static void store(const ControlValue &value, ByteStreamBuffer &buffer);
 	static void store(const ControlInfo &info, ByteStreamBuffer &buffer);
 
+	void populateControlValueEntry(struct ipa_control_value_entry &entry,
+				       const ControlValue &value,
+				       uint32_t offset);
+
 	ControlValue loadControlValue(ByteStreamBuffer &buffer,
-				      bool isArray = false, unsigned int count = 1);
-	ControlInfo loadControlInfo(ByteStreamBuffer &buffer);
+				      ControlType type,
+				      bool isArray, unsigned int count);
 
 	unsigned int serial_;
 	unsigned int serialSeed_;

include/libcamera/ipa/ipa_controls.h

@@ -15,7 +15,7 @@ namespace libcamera {
 extern "C" {
 #endif
 
-#define IPA_CONTROLS_FORMAT_VERSION	1
+#define IPA_CONTROLS_FORMAT_VERSION	2
 
 enum ipa_controls_id_map_type {
 	IPA_CONTROL_ID_MAP_CONTROLS,
@@ -34,20 +34,25 @@ struct ipa_controls_header {
 };
 
 struct ipa_control_value_entry {
-	uint32_t id;
 	uint8_t type;
 	uint8_t is_array;
 	uint16_t count;
 	uint32_t offset;
 	uint32_t padding[1];
+	uint32_t reserved;
+};
+
+struct ipa_control_list_entry {
+	uint32_t id;
+	struct ipa_control_value_entry value;
 };
 
 struct ipa_control_info_entry {
 	uint32_t id;
 	uint32_t type;
-	uint32_t offset;
 	uint8_t direction;
 	uint8_t padding[3];
+	uint32_t reserved;
 };
 
 #ifdef __cplusplus

src/libcamera/control_serializer.cpp

@@ -144,7 +144,7 @@ void ControlSerializer::reset()
 
 size_t ControlSerializer::binarySize(const ControlValue &value)
 {
-	return sizeof(ControlType) + value.data().size_bytes();
+	return value.data().size_bytes();
 }
 
 size_t ControlSerializer::binarySize(const ControlInfo &info)
@@ -164,7 +164,8 @@ size_t ControlSerializer::binarySize(const ControlInfo &info)
 size_t ControlSerializer::binarySize(const ControlInfoMap &infoMap)
 {
 	size_t size = sizeof(struct ipa_controls_header)
-		    + infoMap.size() * sizeof(struct ipa_control_info_entry);
+		    + infoMap.size() * (sizeof(struct ipa_control_info_entry) +
+					3 * sizeof(struct ipa_control_value_entry));
 
 	for (const auto &ctrl : infoMap)
 		size += binarySize(ctrl.second);
@@ -184,7 +185,7 @@ size_t ControlSerializer::binarySize(const ControlInfoMap &infoMap)
 size_t ControlSerializer::binarySize(const ControlList &list)
 {
 	size_t size = sizeof(struct ipa_controls_header)
-		    + list.size() * sizeof(struct ipa_control_value_entry);
+		    + list.size() * sizeof(struct ipa_control_list_entry);
 
 	for (const auto &ctrl : list)
 		size += binarySize(ctrl.second);
@@ -195,16 +196,17 @@ size_t ControlSerializer::binarySize(const ControlList &list)
 void ControlSerializer::store(const ControlValue &value,
 			      ByteStreamBuffer &buffer)
 {
-	const ControlType type = value.type();
-	buffer.write(&type);
 	buffer.write(value.data());
 }
 
-void ControlSerializer::store(const ControlInfo &info, ByteStreamBuffer &buffer)
+void ControlSerializer::populateControlValueEntry(struct ipa_control_value_entry &entry,
+						  const ControlValue &value,
+						  uint32_t offset)
 {
-	store(info.min(), buffer);
-	store(info.max(), buffer);
-	store(info.def(), buffer);
+	entry.type = value.type();
+	entry.is_array = value.isArray();
+	entry.count = value.numElements();
+	entry.offset = offset;
 }
 
 /**
@@ -232,7 +234,8 @@ int ControlSerializer::serialize(const ControlInfoMap &infoMap,
 
 	/* Compute entries and data required sizes. */
 	size_t entriesSize = infoMap.size()
-			   * sizeof(struct ipa_control_info_entry);
+			   * (sizeof(struct ipa_control_info_entry) +
+			      3 * sizeof(struct ipa_control_value_entry));
 	size_t valuesSize = 0;
 	for (const auto &ctrl : infoMap)
 		valuesSize += binarySize(ctrl.second);
@@ -280,11 +283,32 @@ int ControlSerializer::serialize(const ControlInfoMap &infoMap,
 		struct ipa_control_info_entry entry;
 		entry.id = id->id();
 		entry.type = id->type();
-		entry.offset = values.offset();
 		entry.direction = static_cast<ControlId::DirectionFlags::Type>(id->direction());
 		entries.write(&entry);
 
-		store(info, values);
+		/*
+		 * Write the metadata for the ControlValue entries as well,
+		 * since we need type, isArray, and numElements information for
+		 * min/max/def of the ControlInfo. Doing it this way is the
+		 * least intrusive in terms of changing the structs in
+		 * ipa_controls.h
+		 */
+		struct ipa_control_value_entry valueEntry;
+
+		populateControlValueEntry(valueEntry, info.min(),
+					  values.offset());
+		entries.write(&valueEntry);
+		store(info.min(), values);
+
+		populateControlValueEntry(valueEntry, info.max(),
+					  values.offset());
+		entries.write(&valueEntry);
+		store(info.max(), values);
+
+		populateControlValueEntry(valueEntry, info.def(),
+					  values.offset());
+		entries.write(&valueEntry);
+		store(info.def(), values);
 	}
 
 	if (buffer.overflow())
@@ -341,7 +365,7 @@ int ControlSerializer::serialize(const ControlList &list,
 	else
 		idMapType = IPA_CONTROL_ID_MAP_V4L2;
 
-	size_t entriesSize = list.size() * sizeof(struct ipa_control_value_entry);
+	size_t entriesSize = list.size() * sizeof(struct ipa_control_list_entry);
 	size_t valuesSize = 0;
 	for (const auto &ctrl : list)
 		valuesSize += binarySize(ctrl.second);
@@ -365,12 +389,9 @@ int ControlSerializer::serialize(const ControlList &list,
 		unsigned int id = ctrl.first;
 		const ControlValue &value = ctrl.second;
 
-		struct ipa_control_value_entry entry;
+		struct ipa_control_list_entry entry;
 		entry.id = id;
-		entry.type = value.type();
-		entry.is_array = value.isArray();
-		entry.count = value.numElements();
-		entry.offset = values.offset();
+		populateControlValueEntry(entry.value, value, values.offset());
 		entries.write(&entry);
 
 		store(value, values);
@@ -383,12 +404,10 @@ int ControlSerializer::serialize(const ControlList &list,
 }
 
 ControlValue ControlSerializer::loadControlValue(ByteStreamBuffer &buffer,
+						 ControlType type,
 						 bool isArray,
 						 unsigned int count)
 {
-	ControlType type;
-	buffer.read(&type);
-
 	ControlValue value;
 
 	value.reserve(type, isArray, count);
@@ -397,15 +416,6 @@ ControlValue ControlSerializer::loadControlValue(ByteStreamBuffer &buffer,
 	return value;
 }
 
-ControlInfo ControlSerializer::loadControlInfo(ByteStreamBuffer &b)
-{
-	ControlValue min = loadControlValue(b);
-	ControlValue max = loadControlValue(b);
-	ControlValue def = loadControlValue(b);
-
-	return ControlInfo(min, max, def);
-}
-
 /**
  * \fn template<typename T> T ControlSerializer::deserialize(ByteStreamBuffer &buffer)
  * \brief Deserialize an object from a binary buffer
@@ -483,9 +493,11 @@ ControlInfoMap ControlSerializer::deserialize<ControlInfoMap>(ByteStreamBuffer &
 
 	ControlInfoMap::Map ctrls;
 	for (unsigned int i = 0; i < hdr->entries; ++i) {
-		const struct ipa_control_info_entry *entry =
-			entries.read<decltype(*entry)>();
-		if (!entry) {
+		const auto *entry = entries.read<const ipa_control_info_entry>();
+		const auto *min_entry = entries.read<const ipa_control_value_entry>();
+		const auto *max_entry = entries.read<const ipa_control_value_entry>();
+		const auto *def_entry = entries.read<const ipa_control_value_entry>();
+		if (!entry || !min_entry || !max_entry || !def_entry) {
 			LOG(Serializer, Error) << "Out of data";
 			return {};
 		}
@@ -511,15 +523,39 @@ ControlInfoMap ControlSerializer::deserialize<ControlInfoMap>(ByteStreamBuffer &
 		const ControlId *controlId = idMap->at(entry->id);
 		ASSERT(controlId);
 
-		if (entry->offset != values.offset()) {
+		if (min_entry->offset != values.offset()) {
 			LOG(Serializer, Error)
-				<< "Bad data, entry offset mismatch (entry "
+				<< "Bad data, entry offset mismatch (min entry "
+				<< i << ")";
+			return {};
+		}
+		ControlValue min =
+			loadControlValue(values, static_cast<ControlType>(min_entry->type),
+					 min_entry->is_array, min_entry->count);
+
+		if (max_entry->offset != values.offset()) {
+			LOG(Serializer, Error)
+				<< "Bad data, entry offset mismatch (max entry "
 				<< i << ")";
 			return {};
 		}
+		ControlValue max =
+			loadControlValue(values, static_cast<ControlType>(max_entry->type),
+					 max_entry->is_array, max_entry->count);
+
+		if (def_entry->offset != values.offset()) {
+			LOG(Serializer, Error)
+				<< "Bad data, entry offset mismatch (def entry "
+				<< i << ")";
+			return {};
+		}
+		ControlValue def =
+			loadControlValue(values, static_cast<ControlType>(def_entry->type),
+					 def_entry->is_array, def_entry->count);
+
 
 		/* Create and store the ControlInfo. */
-		ctrls.emplace(controlId, loadControlInfo(values));
+		ctrls.emplace(controlId, ControlInfo(min, max, def));
 	}
 
 	/*
@@ -618,12 +654,12 @@ ControlList ControlSerializer::deserialize<ControlList>(ByteStreamBuffer &buffer
 	ControlList ctrls(*idMap);
 
 	for (unsigned int i = 0; i < hdr->entries; ++i) {
-		const struct ipa_control_value_entry *entry =
-			entries.read<decltype(*entry)>();
-		if (!entry) {
+		auto *list_entry = entries.read<const ipa_control_list_entry>();
+		if (!list_entry) {
 			LOG(Serializer, Error) << "Out of data";
 			return {};
 		}
+		const ipa_control_value_entry *entry = &list_entry->value;
 
 		if (entry->offset != values.offset()) {
 			LOG(Serializer, Error)
@@ -632,8 +668,9 @@ ControlList ControlSerializer::deserialize<ControlList>(ByteStreamBuffer &buffer
 			return {};
 		}
 
-		ctrls.set(entry->id,
-			  loadControlValue(values, entry->is_array, entry->count));
+		ctrls.set(list_entry->id,
+			  loadControlValue(values, static_cast<ControlType>(entry->type),
+					   entry->is_array, entry->count));
 	}
 
 	return ctrls;

src/libcamera/ipa_controls.cpp

@@ -192,8 +192,6 @@ static_assert(sizeof(ipa_controls_header) == 32,
 /**
  * \struct ipa_control_value_entry
  * \brief Description of a serialized ControlValue entry
- * \var ipa_control_value_entry::id
- * The numerical ID of the control
  * \var ipa_control_value_entry::type
  * The type of the control (defined by enum ControlType)
  * \var ipa_control_value_entry::is_array
@@ -205,27 +203,41 @@ static_assert(sizeof(ipa_controls_header) == 32,
  * value data (shall be a multiple of 8 bytes).
  * \var ipa_control_value_entry::padding
  * Padding bytes (shall be set to 0)
+ * \var ipa_control_value_entry::reserved
+ * Reserved for future extensions
  */
 
 static_assert(sizeof(ipa_control_value_entry) == 16,
 	      "Invalid ABI size change for struct ipa_control_value_entry");
 
+/**
+ * \struct ipa_control_list_entry
+ * \brief Description of a serialized ControlList entry
+ * \var ipa_control_list_entry::id
+ * The numerical ID of the control
+ * \var ipa_control_list_entry::value
+ * The description of the serialized ControlValue
+ */
+
+static_assert(sizeof(ipa_control_list_entry) == 20,
+	      "Invalid ABI size change for struct ipa_control_list_entry");
+
 /**
  * \struct ipa_control_info_entry
  * \brief Description of a serialized ControlInfo entry
  * \var ipa_control_info_entry::id
  * The numerical ID of the control
  * \var ipa_control_info_entry::type
  * The type of the control (defined by enum ControlType)
- * \var ipa_control_info_entry::offset
- * The offset in bytes from the beginning of the data section to the control
  * info data (shall be a multiple of 8 bytes)
  * \var ipa_control_info_entry::direction
  * The directions in which the control is allowed to be sent. This is a flags
  * value, where 0x1 signifies input (as controls), and 0x2 signifies output (as
  * metadata). \sa ControlId::Direction
  * \var ipa_control_info_entry::padding
  * Padding bytes (shall be set to 0)
+ * \var ipa_control_info_entry::reserved
+ * Reserved for future extensions
  */
 
 static_assert(sizeof(ipa_control_info_entry) == 16,