[libcamera-devel] [PATCH] pipeline: raspberrypi: Add a sensor dequeue timeout

[Naushir Patuck]

Add a timer to the pipeline handler that get set on start(), and subsequently
reset on each frame dequeue from the sensor. If the timeout expires, log an
error message indicating so. This is useful for debugging sensor failures were
the device just stops streaming frames to Unicam, or the pipeline handler has
failed to queue buffers to the Unicam device driver.

The timeout is calculated as 2x the maximum frame length possible for a given
mode.

Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
---
 include/libcamera/ipa/raspberrypi.mojom       |  1 +
 src/ipa/raspberrypi/raspberrypi.cpp           |  7 ++++++
 .../pipeline/raspberrypi/raspberrypi.cpp      | 22 +++++++++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/include/libcamera/ipa/raspberrypi.mojom b/include/libcamera/ipa/raspberrypi.mojom
index acd3cafe6c91..33d2a97ca916 100644
--- a/include/libcamera/ipa/raspberrypi.mojom
+++ b/include/libcamera/ipa/raspberrypi.mojom
@@ -41,6 +41,7 @@ struct IPAConfig {
 struct StartConfig {
 	libcamera.ControlList controls;
 	int32 dropFrameCount;
+	uint32 sensorTimeoutMs;
 };
 
 interface IPARPiInterface {
diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
index fd8fecb07f81..983d6e998b4c 100644
--- a/src/ipa/raspberrypi/raspberrypi.cpp
+++ b/src/ipa/raspberrypi/raspberrypi.cpp
@@ -281,6 +281,13 @@ void IPARPi::start(const ControlList &controls, ipa::RPi::StartConfig *startConf
 
 	startConfig->dropFrameCount = dropFrameCount_;
 
+	/*
+	 * Set the pipeline handler's sensor timeout to 2x the maximum possible
+	 * frame duration for this mode.
+	 */
+	const Duration maxSensorFrameDuration = mode_.max_frame_length * mode_.line_length;
+	startConfig->sensorTimeoutMs = 2 * maxSensorFrameDuration.get<std::milli>();
+
 	firstStart_ = false;
 	lastRunTimestamp_ = 0;
 }
diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
index c2230199fed7..86d952b52aed 100644
--- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
+++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
@@ -15,6 +15,7 @@
 #include <utility>
 
 #include <libcamera/base/shared_fd.h>
+#include <libcamera/base/timer.h>
 #include <libcamera/base/utils.h>
 
 #include <libcamera/camera.h>
@@ -202,6 +203,7 @@ public:
 	void setIspControls(const ControlList &controls);
 	void setDelayedControls(const ControlList &controls);
 	void setSensorControls(ControlList &controls);
+	void sensorTimeout();
 
 	/* bufferComplete signal handlers. */
 	void unicamBufferDequeue(FrameBuffer *buffer);
@@ -279,6 +281,10 @@ public:
 	 */
 	std::optional<int32_t> notifyGainsUnity_;
 
+	/* Timer to ensure the sensor is producing frames for the pipeline handler. */
+	Timer sensorTimeout_;
+	std::chrono::milliseconds sensorTimeoutDuration_;
+
 private:
 	void checkRequestCompleted();
 	void fillRequestMetadata(const ControlList &bufferControls,
@@ -1032,6 +1038,11 @@ int PipelineHandlerRPi::start(Camera *camera, const ControlList *controls)
 		}
 	}
 
+	LOG(RPI, Debug) << "Setting sensor timeout to " << startConfig.sensorTimeoutMs << " ms";
+	data->sensorTimeoutDuration_ = std::chrono::milliseconds(startConfig.sensorTimeoutMs);
+	data->sensorTimeout_.start(data->sensorTimeoutDuration_);
+	data->sensorTimeout_.timeout.connect(data, &RPiCameraData::sensorTimeout);
+
 	return 0;
 }
 
@@ -1040,6 +1051,8 @@ void PipelineHandlerRPi::stopDevice(Camera *camera)
 	RPiCameraData *data = cameraData(camera);
 
 	data->state_ = RPiCameraData::State::Stopped;
+	data->sensorTimeout_.timeout.disconnect();
+	data->sensorTimeout_.stop();
 
 	/* Disable SOF event generation. */
 	data->unicam_[Unicam::Image].dev()->setFrameStartEnabled(false);
@@ -1757,6 +1770,12 @@ void RPiCameraData::setSensorControls(ControlList &controls)
 	sensor_->setControls(&controls);
 }
 
+void RPiCameraData::sensorTimeout()
+{
+	LOG(RPI, Error) << "Sensor has timed out after "
+			<< sensorTimeoutDuration_.count() << " ms!";
+}
+
 void RPiCameraData::unicamBufferDequeue(FrameBuffer *buffer)
 {
 	RPi::Stream *stream = nullptr;
@@ -1792,6 +1811,9 @@ void RPiCameraData::unicamBufferDequeue(FrameBuffer *buffer)
 		 */
 		ctrl.set(controls::SensorTimestamp, buffer->metadata().timestamp);
 		bayerQueue_.push({ buffer, std::move(ctrl) });
+
+		/* Restart the sensor timer. */
+		sensorTimeout_.start(sensorTimeoutDuration_);
 	} else {
 		embeddedQueue_.push(buffer);
 	}
-- 
2.25.1