libcamera: pipeline: simple: Open all video devices at match() time

Move opening of video devices at match() time, the same way as subdevs
are opened, to make the handling of V4L2 video devices and subdevices
more consistent.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Martin Kepplinger <martin.kepplinger@puri.sm>

1 files changed, 33 insertions, 34 deletions

diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp
index c3fd7e1f..1c53de5c 100644
--- a/src/libcamera/pipeline/simple/simple.cpp
+++ b/src/libcamera/pipeline/simple/simple.cpp
@@ -83,14 +83,12 @@ LOG_DEFINE_CATEGORY(SimplePipeline)
  * handled by this heuristic.
  *
  * Once the camera data instances have been created, the match() function
- * creates a V4L2Subdevice instance for each entity used by any of the cameras
- * and stores the instances in SimplePipelineHandler::subdevs_, accessible by
- * the SimpleCameraData class through the SimplePipelineHandler::subdev()
- * function. This avoids duplication of subdev instances between different
- * cameras when the same entity is used in multiple paths. A similar mechanism
- * is used for V4L2VideoDevice instances, but instances are in this case created
- * on demand when accessed through SimplePipelineHandler::video() instead of all
- * in one go at initialization time.
+ * creates a V4L2VideoDevice or V4L2Subdevice instance for each entity used by
+ * any of the cameras and stores them in SimplePipelineHandler::entities_,
+ * accessible by the SimpleCameraData class through the
+ * SimplePipelineHandler::subdev() and SimplePipelineHandler::video() functions.
+ * This avoids duplication of subdev instances between different cameras when
+ * the same entity is used in multiple paths.
  *
  * Finally, all camera data instances are initialized to gather information
  * about the possible pipeline configurations for the corresponding camera. If
@@ -403,10 +401,7 @@ int SimpleCameraData::init()
 	int ret;
 
 	video_ = pipe->video(entities_.back().entity);
-	if (!video_) {
-		LOG(SimplePipeline, Error) << "Failed to open video device";
-		return -ENODEV;
-	}
+	ASSERT(video_);
 
 	/*
 	 * Setup links first as some subdev drivers take active links into
@@ -1074,24 +1069,44 @@ bool SimplePipelineHandler::match(DeviceEnumerator *enumerator)
 
 	/*
 	 * Insert all entities in the global entities list. Create and open
-	 * V4L2Subdevice instances for each entity corresponding to a V4L2
-	 * subdevice.
+	 * V4L2VideoDevice and V4L2Subdevice instances for the corresponding
+	 * entities.
 	 */
 	for (MediaEntity *entity : entities) {
+		std::unique_ptr<V4L2VideoDevice> video;
 		std::unique_ptr<V4L2Subdevice> subdev;
+		int ret;
+
+		switch (entity->type()) {
+		case MediaEntity::Type::V4L2VideoDevice:
+			video = std::make_unique<V4L2VideoDevice>(entity);
+			ret = video->open();
+			if (ret < 0) {
+				LOG(SimplePipeline, Error)
+					<< "Failed to open " << video->deviceNode()
+					<< ": " << strerror(-ret);
+				return false;
+			}
+
+			video->bufferReady.connect(this, &SimplePipelineHandler::bufferReady);
+			break;
 
-		if (entity->type() == MediaEntity::Type::V4L2Subdevice) {
+		case MediaEntity::Type::V4L2Subdevice:
 			subdev = std::make_unique<V4L2Subdevice>(entity);
-			int ret = subdev->open();
+			ret = subdev->open();
 			if (ret < 0) {
 				LOG(SimplePipeline, Error)
 					<< "Failed to open " << subdev->deviceNode()
 					<< ": " << strerror(-ret);
 				return false;
 			}
+			break;
+
+		default:
+			break;
 		}
 
-		entities_[entity] = { nullptr, std::move(subdev) };
+		entities_[entity] = { std::move(video), std::move(subdev) };
 	}
 
 	/* Initialize each pipeline and register a corresponding camera. */
@@ -1119,27 +1134,11 @@ bool SimplePipelineHandler::match(DeviceEnumerator *enumerator)
 
 V4L2VideoDevice *SimplePipelineHandler::video(const MediaEntity *entity)
 {
-	/*
-	 * Return the V4L2VideoDevice corresponding to the media entity, either
-	 * as a previously constructed device if available from the cache, or
-	 * by constructing a new one.
-	 */
-
 	auto iter = entities_.find(entity);
 	if (iter == entities_.end())
 		return nullptr;
 
-	EntityData &data = iter->second;
-	if (data.video)
-		return data.video.get();
-
-	data.video = std::make_unique<V4L2VideoDevice>(entity);
-	if (data.video->open() < 0)
-		return nullptr;
-
-	data.video->bufferReady.connect(this, &SimplePipelineHandler::bufferReady);
-
-	return data.video.get();
+	return iter->second.video.get();
 }
 
 V4L2Subdevice *SimplePipelineHandler::subdev(const MediaEntity *entity)