[libcamera-devel] [PATCH v1 3/3] pipeline: raspberrypi: Add a Unicam dequeue timeout

[Naushir Patuck]

Enable the V4L2VideoDevice dequeue timeout for the Unicam Image node, and
connect the timeout signal to a slot in the pipeline handler. This slot will
log a fatal error message informing the user of a possible hardware stall.

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

Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
---
 include/libcamera/ipa/raspberrypi.mojom           |  1 +
 src/ipa/raspberrypi/raspberrypi.cpp               |  2 ++
 .../pipeline/raspberrypi/raspberrypi.cpp          | 15 +++++++++++++++
 3 files changed, 18 insertions(+)

diff --git a/include/libcamera/ipa/raspberrypi.mojom b/include/libcamera/ipa/raspberrypi.mojom
index acd3cafe6c91..5a228b75cd2f 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 maxSensorFrameLengthMs;
 };
 
 interface IPARPiInterface {
diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
index fd8fecb07f81..675f9ba1b350 100644
--- a/src/ipa/raspberrypi/raspberrypi.cpp
+++ b/src/ipa/raspberrypi/raspberrypi.cpp
@@ -280,6 +280,8 @@ void IPARPi::start(const ControlList &controls, ipa::RPi::StartConfig *startConf
 	}
 
 	startConfig->dropFrameCount = dropFrameCount_;
+	const Duration maxSensorFrameDuration = mode_.max_frame_length * mode_.line_length;
+	startConfig->maxSensorFrameLengthMs = 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..50b39f1adf93 100644
--- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
+++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
@@ -45,6 +45,8 @@
 #include "dma_heaps.h"
 #include "rpi_stream.h"
 
+using namespace std::literals::chrono_literals;
+
 namespace libcamera {
 
 LOG_DEFINE_CATEGORY(RPI)
@@ -202,6 +204,7 @@ public:
 	void setIspControls(const ControlList &controls);
 	void setDelayedControls(const ControlList &controls);
 	void setSensorControls(ControlList &controls);
+	void unicamTimeout(V4L2VideoDevice *dev);
 
 	/* bufferComplete signal handlers. */
 	void unicamBufferDequeue(FrameBuffer *buffer);
@@ -1032,6 +1035,12 @@ int PipelineHandlerRPi::start(Camera *camera, const ControlList *controls)
 		}
 	}
 
+	/* Set the dequeue timeout to 2x the maximum possible frame duration. */
+	utils::Duration duration = startConfig.maxSensorFrameLengthMs * 2 * 1ms;
+	data->unicam_[Unicam::Image].dev()->setDequeueTimeout(duration);
+	data->unicam_[Unicam::Image].dev()->dequeueTimeout.connect(data, &RPiCameraData::unicamTimeout);
+	LOG(RPI, Debug) << "Setting sensor timeout to " << duration;
+
 	return 0;
 }
 
@@ -1040,6 +1049,7 @@ void PipelineHandlerRPi::stopDevice(Camera *camera)
 	RPiCameraData *data = cameraData(camera);
 
 	data->state_ = RPiCameraData::State::Stopped;
+	data->unicam_[Unicam::Image].dev()->dequeueTimeout.disconnect();
 
 	/* Disable SOF event generation. */
 	data->unicam_[Unicam::Image].dev()->setFrameStartEnabled(false);
@@ -1757,6 +1767,11 @@ void RPiCameraData::setSensorControls(ControlList &controls)
 	sensor_->setControls(&controls);
 }
 
+void RPiCameraData::unicamTimeout([[maybe_unused]] V4L2VideoDevice *dev)
+{
+	LOG(RPI, Fatal) << "Unicam has timed out!";
+}
+
 void RPiCameraData::unicamBufferDequeue(FrameBuffer *buffer)
 {
 	RPi::Stream *stream = nullptr;
-- 
2.25.1