[libcamera-devel] [PATCH v1 5/6] pipeline: raspberrypi: Repurpose RPi::Stream::reset()

[Naushir Patuck]

The original use of RPi::Stream::reset() was to clear the external flag state
and free/clear out the framebuffers for the stream. However, the latter is now
done through PipelineHandlerRPi::configure(). Rework
PipelineHandlerRPi::configure() to call RPi::Stream::setExternal() instead of
RPi::Stream::reset() to achieve the same thing.

Repurpose RPi::Stream::reset() to instead reset the state of the buffer handling
logic, where all internally allocated buffers are put back into the queue of
available buffers. This reset() is now called from PipelineHandlerRPi::start(),
allowing the pipeline handler to correctly deal with start()/stop()/start()
sequences and reusing the buffers allocated on the first start().

Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
---
 src/libcamera/pipeline/raspberrypi/raspberrypi.cpp |  5 ++++-
 src/libcamera/pipeline/raspberrypi/rpi_stream.cpp  | 11 +++++------
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
index b17ffa235ac7..193361686d3c 100644
--- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
+++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
@@ -692,7 +692,7 @@ int PipelineHandlerRPi::configure(Camera *camera, CameraConfiguration *config)
 	/* Start by freeing all buffers and resetting the Unicam and ISP stream states. */
 	data->freeBuffers();
 	for (auto const stream : data->streams_)
-		stream->reset();
+		stream->setExternal(false);
 
 	BayerFormat::Packing packing = BayerFormat::Packing::CSI2;
 	Size maxSize, sensorSize;
@@ -985,6 +985,9 @@ int PipelineHandlerRPi::start(Camera *camera, const ControlList *controls)
 	RPiCameraData *data = cameraData(camera);
 	int ret;
 
+	for (auto const stream : data->streams_)
+		stream->reset();
+
 	if (data->reconfigured_) {
 		/* Allocate buffers for internal pipeline usage. */
 		ret = prepareBuffers(camera);
diff --git a/src/libcamera/pipeline/raspberrypi/rpi_stream.cpp b/src/libcamera/pipeline/raspberrypi/rpi_stream.cpp
index f446e1ce66c7..0840ec4f54a0 100644
--- a/src/libcamera/pipeline/raspberrypi/rpi_stream.cpp
+++ b/src/libcamera/pipeline/raspberrypi/rpi_stream.cpp
@@ -28,8 +28,10 @@ std::string Stream::name() const
 
 void Stream::reset()
 {
-	external_ = false;
-	clearBuffers();
+	/* Add all internal buffers to the queue of usable buffers. */
+	availableBuffers_ = {};
+	for (auto const &buffer : internalBuffers_)
+		availableBuffers_.push(buffer.get());
 }
 
 void Stream::setExternal(bool external)
@@ -97,10 +99,7 @@ int Stream::prepareBuffers(unsigned int count)
 
 			/* Add these exported buffers to the internal/external buffer list. */
 			setExportedBuffers(&internalBuffers_);
-
-			/* Add these buffers to the queue of internal usable buffers. */
-			for (auto const &buffer : internalBuffers_)
-				availableBuffers_.push(buffer.get());
+			reset();
 		}
 
 		/* We must import all internal/external exported buffers. */
-- 
2.25.1