[libcamera-devel] [PATCH v5 2/3] 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 an 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>
Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
 include/libcamera/ipa/raspberrypi.mojom       |  1 +
 src/ipa/raspberrypi/raspberrypi.cpp           |  2 ++
 .../pipeline/raspberrypi/raspberrypi.cpp      | 19 +++++++++++++++++++
 3 files changed, 22 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 1bf4e270b062..89767a9db471 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 8fd79be67988..d6148724bdd5 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::chrono_literals;
+
 namespace libcamera {
 
 LOG_DEFINE_CATEGORY(RPI)
@@ -208,6 +210,7 @@ public:
 	void setIspControls(const ControlList &controls);
 	void setDelayedControls(const ControlList &controls);
 	void setSensorControls(ControlList &controls);
+	void unicamTimeout();
 
 	/* bufferComplete signal handlers. */
 	void unicamBufferDequeue(FrameBuffer *buffer);
@@ -1050,6 +1053,14 @@ int PipelineHandlerRPi::start(Camera *camera, const ControlList *controls)
 		}
 	}
 
+	/*
+	 * Set the dequeue timeout to the larger of 2x the maximum possible
+	 * frame duration or 1 second.
+	 */
+	utils::Duration timeout =
+		std::max<utils::Duration>(1s, 2 * startConfig.maxSensorFrameLengthMs * 1ms);
+	data->unicam_[Unicam::Image].dev()->setDequeueTimeout(timeout);
+
 	return 0;
 }
 
@@ -1192,6 +1203,7 @@ int PipelineHandlerRPi::registerCamera(MediaDevice *unicam, MediaDevice *isp, Me
 	data->isp_[Isp::Stats] = RPi::Stream("ISP Stats", ispCapture3);
 
 	/* Wire up all the buffer connections. */
+	data->unicam_[Unicam::Image].dev()->dequeueTimeout.connect(data.get(), &RPiCameraData::unicamTimeout);
 	data->unicam_[Unicam::Image].dev()->frameStart.connect(data.get(), &RPiCameraData::frameStarted);
 	data->unicam_[Unicam::Image].dev()->bufferReady.connect(data.get(), &RPiCameraData::unicamBufferDequeue);
 	data->isp_[Isp::Input].dev()->bufferReady.connect(data.get(), &RPiCameraData::ispInputDequeue);
@@ -1773,6 +1785,13 @@ void RPiCameraData::setSensorControls(ControlList &controls)
 	sensor_->setControls(&controls);
 }
 
+void RPiCameraData::unicamTimeout()
+{
+	LOG(RPI, Error) << "Unicam has timed out!";
+	LOG(RPI, Error) << "Please check that your camera sensor connector is attached securely.";
+	LOG(RPI, Error) << "Alternatively, try another cable and/or sensor.";
+}
+
 void RPiCameraData::unicamBufferDequeue(FrameBuffer *buffer)
 {
 	RPi::Stream *stream = nullptr;
-- 
2.25.1