libcamera: media_device: Open and close media device inside populate()

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 resources would not be deleted if the
second MEDIA_IOC_G_TOPOLOGY would fail.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

5 files changed, 12 insertions, 29 deletions

diff --git a/src/libcamera/device_enumerator.cpp b/src/libcamera/device_enumerator.cpp
index 259eec41..6fcbae76 100644
--- a/src/libcamera/device_enumerator.cpp
+++ b/src/libcamera/device_enumerator.cpp
@@ -207,11 +207,7 @@ 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
@@ -238,8 +234,6 @@ 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 449571fb..c3977516 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.
 	 */
@@ -237,7 +241,7 @@ int MediaDevice::populate()
 			LOG(MediaDevice, Error)
 				<< "Failed to enumerate topology: "
 				<< strerror(-ret);
-			return ret;
+			goto done;
 		}
 
 		if (version == topology.topology_version)
@@ -262,6 +266,10 @@ int MediaDevice::populate()
 	    populateLinks(topology))
 		valid_ = true;
 
+	ret = 0;
+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 3eef9739..ceffd538 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 953f0233..1d4cc4d4 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_subdevice/v4l2_subdevice_test.cpp b/test/v4l2_subdevice/v4l2_subdevice_test.cpp
index 5810ef3c..562a638c 100644
--- a/test/v4l2_subdevice/v4l2_subdevice_test.cpp
+++ b/test/v4l2_subdevice/v4l2_subdevice_test.cpp
@@ -45,13 +45,6 @@ int V4L2SubdeviceTest::init()
 		return TestSkip;
 	}
 
-	int ret = media_->open();
-	if (ret) {
-		cerr << "Unable to open media device: " << media_->deviceNode()
-		     << ": " << strerror(ret) << endl;
-		return TestSkip;
-	}
-
 	MediaEntity *videoEntity = media_->getEntityByName("Scaler");
 	if (!videoEntity) {
 		cerr << "Unable to find media entity 'Scaler'" << endl;
@@ -59,8 +52,7 @@ int V4L2SubdeviceTest::init()
 	}
 
 	scaler_ = new V4L2Subdevice(videoEntity);
-	ret = scaler_->open();
-	if (ret) {
+	if (scaler_->open()) {
 		cerr << "Unable to open video subdevice "
 		     << scaler_->entity()->deviceNode() << endl;
 		return TestSkip;