libcamera: pipeline: ipu3: Cancel unused buffers

When the CIO2 returns a cancelled buffer, we will not queue buffers
to the IMGU.

These buffers should be explicitly marked as cancelled to ensure
the application knows there is no valid metadata or frame data
provided in the buffer.

Provide a cancel() method on the FrameBuffer to allow explicitly
cancelling a buffer.

Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

3 files changed, 15 insertions, 2 deletions

diff --git a/include/libcamera/buffer.h b/include/libcamera/buffer.h
index 620f8a66..e0af0090 100644
--- a/include/libcamera/buffer.h
+++ b/include/libcamera/buffer.h
@@ -53,6 +53,8 @@ public:
 	unsigned int cookie() const { return cookie_; }
 	void setCookie(unsigned int cookie) { cookie_ = cookie; }
 
+	void cancel() { metadata_.status = FrameMetadata::FrameCancelled; }
+
 private:
 	LIBCAMERA_DISABLE_COPY_AND_MOVE(FrameBuffer)
 
diff --git a/src/libcamera/buffer.cpp b/src/libcamera/buffer.cpp
index 75b26932..7635226b 100644
--- a/src/libcamera/buffer.cpp
+++ b/src/libcamera/buffer.cpp
@@ -227,6 +227,14 @@ FrameBuffer::FrameBuffer(const std::vector<Plane> &planes, unsigned int cookie)
  */
 
 /**
+ * \fn FrameBuffer::cancel()
+ * \brief Marks the buffer as cancelled
+ *
+ * If a buffer is not used by a request, it shall be marked as cancelled to
+ * indicate that the metadata is invalid.
+ */
+
+/**
  * \class MappedBuffer
  * \brief Provide an interface to support managing memory mapped buffers
  *
diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
index 51446fcf..73306cea 100644
--- a/src/libcamera/pipeline/ipu3/ipu3.cpp
+++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
@@ -1257,8 +1257,11 @@ void IPU3CameraData::cio2BufferReady(FrameBuffer *buffer)
 
 	/* If the buffer is cancelled force a complete of the whole request. */
 	if (buffer->metadata().status == FrameMetadata::FrameCancelled) {
-		for (auto it : request->buffers())
-			pipe_->completeBuffer(request, it.second);
+		for (auto it : request->buffers()) {
+			FrameBuffer *b = it.second;
+			b->cancel();
+			pipe_->completeBuffer(request, b);
+		}
 
 		frameInfos_.remove(info);
 		pipe_->completeRequest(request);