5 files changed, 32 insertions, 1 deletions

diff --git a/src/v4l2/v4l2_camera.cpp b/src/v4l2/v4l2_camera.cpp
index 4da01a45..3c369328 100644
--- a/src/v4l2/v4l2_camera.cpp
+++ b/src/v4l2/v4l2_camera.cpp
@@ -8,6 +8,7 @@
 #include "v4l2_camera.h"
 
 #include <errno.h>
+#include <unistd.h>
 
 #include "libcamera/internal/log.h"
 
@@ -53,6 +54,11 @@ void V4L2Camera::close()
 	camera_->release();
 }
 
+void V4L2Camera::bind(int efd)
+{
+	efd_ = efd;
+}
+
 void V4L2Camera::getStreamConfig(StreamConfiguration *streamConfig)
 {
 	*streamConfig = config_->at(0);
@@ -84,6 +90,9 @@ void V4L2Camera::requestComplete(Request *request)
 	completedBuffers_.push_back(std::move(metadata));
 	bufferLock_.unlock();
 
+	uint64_t data = 1;
+	::write(efd_, &data, sizeof(data));
+
 	bufferSema_.release();
 }
 
diff --git a/src/v4l2/v4l2_camera.h b/src/v4l2/v4l2_camera.h
index 303eda44..33f5eb02 100644
--- a/src/v4l2/v4l2_camera.h
+++ b/src/v4l2/v4l2_camera.h
@@ -39,6 +39,7 @@ public:
 
 	int open();
 	void close();
+	void bind(int efd);
 	void getStreamConfig(StreamConfiguration *streamConfig);
 	std::vector<Buffer> completedBuffers();
 
@@ -70,6 +71,8 @@ private:
 
 	std::deque<std::unique_ptr<Request>> pendingRequests_;
 	std::deque<std::unique_ptr<Buffer>> completedBuffers_;
+
+	int efd_;
 };
 
 #endif /* __V4L2_CAMERA_H__ */
diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
index cbe9e026..7ee4c0cb 100644
--- a/src/v4l2/v4l2_camera_proxy.cpp
+++ b/src/v4l2/v4l2_camera_proxy.cpp
@@ -13,6 +13,7 @@
 #include <linux/videodev2.h>
 #include <string.h>
 #include <sys/mman.h>
+#include <unistd.h>
 
 #include <libcamera/camera.h>
 #include <libcamera/object.h>
@@ -451,6 +452,9 @@ int V4L2CameraProxy::vidioc_dqbuf(struct v4l2_buffer *arg)
 
 	currentBuf_ = (currentBuf_ + 1) % bufferCount_;
 
+	uint64_t data;
+	::read(efd_, &data, sizeof(data));
+
 	return 0;
 }
 
@@ -529,6 +533,12 @@ int V4L2CameraProxy::ioctl(unsigned long request, void *arg)
 	return ret;
 }
 
+void V4L2CameraProxy::bind(int fd)
+{
+	efd_ = fd;
+	vcam_->bind(fd);
+}
+
 struct PixelFormatPlaneInfo {
 	unsigned int bitsPerPixel;
 	unsigned int hSubSampling;
diff --git a/src/v4l2/v4l2_camera_proxy.h b/src/v4l2/v4l2_camera_proxy.h
index af9f9bbe..7c65c886 100644
--- a/src/v4l2/v4l2_camera_proxy.h
+++ b/src/v4l2/v4l2_camera_proxy.h
@@ -33,6 +33,8 @@ public:
 
 	int ioctl(unsigned long request, void *arg);
 
+	void bind(int fd);
+
 private:
 	bool validateBufferType(uint32_t type);
 	bool validateMemoryType(uint32_t memory);
@@ -77,6 +79,8 @@ private:
 	std::map<void *, unsigned int> mmaps_;
 
 	std::unique_ptr<V4L2Camera> vcam_;
+
+	int efd_;
 };
 
 #endif /* __V4L2_CAMERA_PROXY_H__ */
diff --git a/src/v4l2/v4l2_compat_manager.cpp b/src/v4l2/v4l2_compat_manager.cpp
index 2338a0ee..56533c4f 100644
--- a/src/v4l2/v4l2_compat_manager.cpp
+++ b/src/v4l2/v4l2_compat_manager.cpp
@@ -155,12 +155,17 @@ int V4L2CompatManager::openat(int dirfd, const char *path, int oflag, mode_t mod
 	if (ret < 0)
 		return ret;
 
-	int efd = eventfd(0, oflag & (O_CLOEXEC | O_NONBLOCK));
+	int efd = eventfd(0, EFD_SEMAPHORE |
+			     ((oflag & O_CLOEXEC) ? EFD_CLOEXEC : 0) |
+			     ((oflag & O_NONBLOCK) ? EFD_NONBLOCK : 0));
 	if (efd < 0) {
+		int err = errno;
 		proxy->close();
+		errno = err;
 		return efd;
 	}
 
+	proxy->bind(efd);
 	devices_.emplace(efd, proxy);
 
 	return efd;