[PATCH v5 3/5] pipeline: simple: Connect and disconnect start frame events

[Stanislaw Gruszka]

Enable frame events on the emitter device during
SimplePipelineHandler::start(), move signal connection there
from SimplePipelineHandler::configure().

Also reset delayed controls on start() to prevent using
stale values.

Accordingly disable/disconnect on SimplePipelineHandler::stopDevice().

This fixes the assertion like below:

../src/libcamera/delayed_controls.cpp:227:
libcamera::ControlList libcamera::DelayedControls::get(uint32_t):
Assertion `info.type() != ControlTypeNone' failed

which can happen rarely at the beginning of streaming when
ControlRingBuffer is not yet filled and there are errors on CSI-2.
In such rare scenario we can have call to DelayedControls::get()
with frame number that exceed number of saved entries. Handing
frame start signal assure we do DelayedConntrols::applyControls()
with (possibly out of sequence) frame number and later call
to DelayedControls::get() will get proper not-empty control entry.

Bug: https://bugs.libcamera.org/show_bug.cgi?id=241
Co-developed-by: Hans de Goede <hdegoede at redhat.com>
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka at linux.intel.com>
---
 src/libcamera/pipeline/simple/simple.cpp | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp
index 063a098f..774c7824 100644
--- a/src/libcamera/pipeline/simple/simple.cpp
+++ b/src/libcamera/pipeline/simple/simple.cpp
@@ -1229,7 +1229,6 @@ int SimplePipelineHandler::configure(Camera *camera, CameraConfiguration *c)
 		static_cast<SimpleCameraConfiguration *>(c);
 	SimpleCameraData *data = cameraData(camera);
 	V4L2VideoDevice *video = data->video_;
-	V4L2Subdevice *frameStartEmitter = data->frameStartEmitter_;
 	int ret;

 	/*
@@ -1300,9 +1299,6 @@ int SimplePipelineHandler::configure(Camera *camera, CameraConfiguration *c)
 	data->delayedCtrls_ =
 		std::make_unique<DelayedControls>(data->sensor_->device(),
 						  params);
-	if (frameStartEmitter)
-		frameStartEmitter->frameStart.connect(data->delayedCtrls_.get(),
-						      &DelayedControls::applyControls);

 	StreamConfiguration inputCfg;
 	inputCfg.pixelFormat = pipeConfig->captureFormat;
@@ -1341,6 +1337,7 @@ int SimplePipelineHandler::start(Camera *camera, [[maybe_unused]] const ControlL
 {
 	SimpleCameraData *data = cameraData(camera);
 	V4L2VideoDevice *video = data->video_;
+	V4L2Subdevice *frameStartEmitter = data->frameStartEmitter_;
 	int ret;

 	const MediaPad *pad = acquirePipeline(data);
@@ -1370,6 +1367,17 @@ int SimplePipelineHandler::start(Camera *camera, [[maybe_unused]] const ControlL

 	video->bufferReady.connect(data, &SimpleCameraData::imageBufferReady);

+	data->delayedCtrls_->reset();
+	if (frameStartEmitter) {
+		ret = frameStartEmitter->setFrameStartEnabled(true);
+		if (ret) {
+			stop(camera);
+			return ret;
+		}
+		frameStartEmitter->frameStart.connect(data->delayedCtrls_.get(),
+						      &DelayedControls::applyControls);
+	}
+
 	ret = video->streamOn();
 	if (ret < 0) {
 		stop(camera);
@@ -1401,6 +1409,13 @@ void SimplePipelineHandler::stopDevice(Camera *camera)
 {
 	SimpleCameraData *data = cameraData(camera);
 	V4L2VideoDevice *video = data->video_;
+	V4L2Subdevice *frameStartEmitter = data->frameStartEmitter_;
+
+	if (frameStartEmitter) {
+		frameStartEmitter->setFrameStartEnabled(false);
+		frameStartEmitter->frameStart.disconnect(data->delayedCtrls_.get(),
+							 &DelayedControls::applyControls);
+	}

 	if (data->useConversion_) {
 		if (data->converter_)
--
2.43.0