[libcamera-devel] [PATCH 02/11] libcamera: media_device: Open and close media device inside populate()

[Niklas Söderlund]

Remove the need for the caller to open and close the media device when
populating the MediaDevice. This is done as an effort to make the usage
of the MediaDevice less error prone and the interface stricter.

The rework also revealed and fixes a potential memory leak in
MediaDevice::populate() where if the second (or later) call to
MEDIA_IOC_G_TOPOLOGY would fail.

Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
 src/libcamera/device_enumerator.cpp           |  8 +------
 src/libcamera/media_device.cpp                | 12 +++++++++--
 test/media_device/media_device_print_test.cpp |  6 ------
 test/pipeline/ipu3/ipu3_pipeline_test.cpp     |  5 -----
 test/v4l2_device/v4l2_device_test.cpp         |  5 -----
 test/v4l2_subdevice/v4l2_subdevice_test.cpp   | 21 +------------------
 6 files changed, 12 insertions(+), 45 deletions(-)

diff --git a/src/libcamera/device_enumerator.cpp b/src/libcamera/device_enumerator.cpp
index f6878b3d58b3f966..caf91dcff6efd564 100644
--- a/src/libcamera/device_enumerator.cpp
+++ b/src/libcamera/device_enumerator.cpp
@@ -205,11 +205,7 @@ int DeviceEnumerator::addDevice(const std::string &deviceNode)
 {
 	std::shared_ptr<MediaDevice> media = std::make_shared<MediaDevice>(deviceNode);
 
-	int ret = media->open();
-	if (ret < 0)
-		return ret;
-
-	ret = media->populate();
+	int ret = media->populate();
 	if (ret < 0) {
 		LOG(DeviceEnumerator, Info)
 			<< "Unable to populate media device " << deviceNode
@@ -236,8 +232,6 @@ int DeviceEnumerator::addDevice(const std::string &deviceNode)
 			return ret;
 	}
 
-	media->close();
-
 	LOG(DeviceEnumerator, Debug)
 		<< "Added device " << deviceNode << ": " << media->driver();
 
diff --git a/src/libcamera/media_device.cpp b/src/libcamera/media_device.cpp
index 449571fb4b78fb94..4b3b8f1fa3e6aaad 100644
--- a/src/libcamera/media_device.cpp
+++ b/src/libcamera/media_device.cpp
@@ -221,6 +221,10 @@ int MediaDevice::populate()
 
 	clear();
 
+	ret = open();
+	if (ret)
+		return ret;
+
 	/*
 	 * Keep calling G_TOPOLOGY until the version number stays stable.
 	 */
@@ -237,8 +241,9 @@ int MediaDevice::populate()
 			LOG(MediaDevice, Error)
 				<< "Failed to enumerate topology: "
 				<< strerror(-ret);
-			return ret;
+			goto done;
 		}
+		ret = 0;
 
 		if (version == topology.topology_version)
 			break;
@@ -262,6 +267,9 @@ int MediaDevice::populate()
 	    populateLinks(topology))
 		valid_ = true;
 
+done:
+	close();
+
 	delete[] ents;
 	delete[] interfaces;
 	delete[] pads;
@@ -272,7 +280,7 @@ int MediaDevice::populate()
 		return -EINVAL;
 	}
 
-	return 0;
+	return ret;
 }
 
 /**
diff --git a/test/media_device/media_device_print_test.cpp b/test/media_device/media_device_print_test.cpp
index 3eef973939201b27..ceffd538e13fca73 100644
--- a/test/media_device/media_device_print_test.cpp
+++ b/test/media_device/media_device_print_test.cpp
@@ -124,10 +124,6 @@ int MediaDevicePrintTest::testMediaDevice(const string deviceNode)
 
 	dev.close();
 
-	ret = dev.open();
-	if (ret)
-		return ret;
-
 	ret = dev.populate();
 	if (ret)
 		return ret;
@@ -135,8 +131,6 @@ int MediaDevicePrintTest::testMediaDevice(const string deviceNode)
 	/* Print out the media graph. */
 	printMediaGraph(dev, cerr);
 
-	dev.close();
-
 	return 0;
 }
 
diff --git a/test/pipeline/ipu3/ipu3_pipeline_test.cpp b/test/pipeline/ipu3/ipu3_pipeline_test.cpp
index 953f0233cde485cb..1d4cc4d4950b8391 100644
--- a/test/pipeline/ipu3/ipu3_pipeline_test.cpp
+++ b/test/pipeline/ipu3/ipu3_pipeline_test.cpp
@@ -71,11 +71,6 @@ int IPU3PipelineTest::init()
 		return TestSkip;
 	}
 
-	if (cio2->open()) {
-		cerr << "Failed to open media device " << cio2->deviceNode() << endl;
-		return TestFail;
-	}
-
 	/*
 	 * Camera sensor are connected to the CIO2 unit.
 	 * Count how many sensors are connected in the system
diff --git a/test/v4l2_device/v4l2_device_test.cpp b/test/v4l2_device/v4l2_device_test.cpp
index 90e5f7a3ee0c0f2f..833038d56ea4631d 100644
--- a/test/v4l2_device/v4l2_device_test.cpp
+++ b/test/v4l2_device/v4l2_device_test.cpp
@@ -46,9 +46,6 @@ int V4L2DeviceTest::init()
 	if (!media_)
 		return TestSkip;
 
-	if (!media_->acquire())
-		return TestSkip;
-
 	MediaEntity *entity = media_->getEntityByName("vivid-000-vid-cap");
 	if (!entity)
 		return TestSkip;
@@ -62,8 +59,6 @@ int V4L2DeviceTest::init()
 
 void V4L2DeviceTest::cleanup()
 {
-	media_->release();
-
 	capture_->streamOff();
 	capture_->releaseBuffers();
 	capture_->close();
diff --git a/test/v4l2_subdevice/v4l2_subdevice_test.cpp b/test/v4l2_subdevice/v4l2_subdevice_test.cpp
index 4e16ab6cf3e5f874..562a638cb28ebfb2 100644
--- a/test/v4l2_subdevice/v4l2_subdevice_test.cpp
+++ b/test/v4l2_subdevice/v4l2_subdevice_test.cpp
@@ -45,33 +45,16 @@ int V4L2SubdeviceTest::init()
 		return TestSkip;
 	}
 
-	if (!media_->acquire()) {
-		cerr << "Unable to acquire media device "
-		     << media_->deviceNode() << endl;
-		return TestSkip;
-	}
-
-	int ret = media_->open();
-	if (ret) {
-		cerr << "Unable to open media device: " << media_->deviceNode()
-		     << ": " << strerror(ret) << endl;
-		media_->release();
-		return TestSkip;
-	}
-
 	MediaEntity *videoEntity = media_->getEntityByName("Scaler");
 	if (!videoEntity) {
 		cerr << "Unable to find media entity 'Scaler'" << endl;
-		media_->release();
 		return TestFail;
 	}
 
 	scaler_ = new V4L2Subdevice(videoEntity);
-	ret = scaler_->open();
-	if (ret) {
+	if (scaler_->open()) {
 		cerr << "Unable to open video subdevice "
 		     << scaler_->entity()->deviceNode() << endl;
-		media_->release();
 		return TestSkip;
 	}
 
@@ -80,7 +63,5 @@ int V4L2SubdeviceTest::init()
 
 void V4L2SubdeviceTest::cleanup()
 {
-	media_->release();
-
 	delete scaler_;
 }
-- 
2.21.0