[libcamera-devel] [PATCH 1/2] libcamera: pipeline_handler: Prepare requests

[Kieran Bingham]

Provide a call allowing requests to be prepared and associated with the
pipeline handler after being constructed by the camera.

This provides an opportunity for the Pipeline Handler to connect any
signals it may be interested in receiveing for the request such as
getting notifications when the request is ready for processing when
using a fence.

While here, update the existing usage of the d pointer in
Camera::createRequest() to match the style of other functions.

Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---
 include/libcamera/internal/pipeline_handler.h |  1 +
 src/libcamera/camera.cpp                      | 14 ++++++++++---
 src/libcamera/pipeline_handler.cpp            | 20 ++++++++++++++++---
 3 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/include/libcamera/internal/pipeline_handler.h b/include/libcamera/internal/pipeline_handler.h
index e5b8ffb4db3d..ef7e1390560f 100644
--- a/include/libcamera/internal/pipeline_handler.h
+++ b/include/libcamera/internal/pipeline_handler.h
@@ -59,6 +59,7 @@ public:
 	void stop(Camera *camera);
 	bool hasPendingRequests(const Camera *camera) const;
 
+	void prepareRequest(Request *request);
 	void queueRequest(Request *request);
 
 	bool completeBuffer(Request *request, FrameBuffer *buffer);
diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp
index 86d84ac0a77d..1a00b34d9d9d 100644
--- a/src/libcamera/camera.cpp
+++ b/src/libcamera/camera.cpp
@@ -1074,12 +1074,20 @@ int Camera::configure(CameraConfiguration *config)
  */
 std::unique_ptr<Request> Camera::createRequest(uint64_t cookie)
 {
-	int ret = _d()->isAccessAllowed(Private::CameraConfigured,
-					Private::CameraRunning);
+	Private *const d = _d();
+
+	int ret = d->isAccessAllowed(Private::CameraConfigured,
+				     Private::CameraRunning);
 	if (ret < 0)
 		return nullptr;
 
-	return std::make_unique<Request>(this, cookie);
+	std::unique_ptr<Request> request = std::make_unique<Request>(this, cookie);
+
+	/* Associate the request with the pipeline handler */
+	if (request)
+		d->pipe_->prepareRequest(request.get());
+
+	return request;
 }
 
 /**
diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index 03e4b9e66aa6..18b59ef27fb6 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -337,6 +337,23 @@ bool PipelineHandler::hasPendingRequests(const Camera *camera) const
 	return !camera->_d()->queuedRequests_.empty();
 }
 
+/**
+ * \fn PipelineHandler::prepareRequest()
+ * \brief Prepare a request for use by the Pipeline Handler
+ * \param[in] request The request to prepare
+ */
+void PipelineHandler::prepareRequest(Request *request)
+{
+	/*
+	 * Connect the request prepared signal to the pipeline handler
+	 * to manage fence based preparations allowing the request
+	 * to inform us when it is ready to be processed by hardware.
+	 */
+	request->_d()->prepared.connect(this, [this]() {
+						doQueueRequests();
+					});
+}
+
 /**
  * \fn PipelineHandler::queueRequest()
  * \brief Queue a request
@@ -366,9 +383,6 @@ void PipelineHandler::queueRequest(Request *request)
 
 	waitingRequests_.push(request);
 
-	request->_d()->prepared.connect(this, [this]() {
-						doQueueRequests();
-					});
 	request->_d()->prepare(300ms);
 }
 
-- 
2.32.0