libcamera: ipu3: imgu: Allocate buffers for stats and param

Instead of preparing for buffer importing allocate buffers that can be
used by an IPA.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/libcamera/pipeline/ipu3/imgu.cpp

@@ -552,20 +552,13 @@ int ImgUDevice::allocateBuffers(unsigned int bufferCount)
 		return ret;
 	}
 
-	ret = param_->importBuffers(bufferCount);
+	ret = param_->allocateBuffers(bufferCount, &paramBuffers_);
 	if (ret < 0) {
 		LOG(IPU3, Error) << "Failed to allocate ImgU param buffers";
 		goto error;
 	}
 
-	/*
-	 * The kernel fails to start if buffers are not either imported or
-	 * allocated for the statistics video device. As statistics buffers are
-	 * not yet used by the pipeline import buffers to save memory.
-	 *
-	 * \todo To be revised when we'll actually use the stat node.
-	 */
-	ret = stat_->importBuffers(bufferCount);
+	ret = stat_->allocateBuffers(bufferCount, &statBuffers_);
 	if (ret < 0) {
 		LOG(IPU3, Error) << "Failed to allocate ImgU stat buffers";
 		goto error;
@@ -603,6 +596,9 @@ void ImgUDevice::freeBuffers()
 {
 	int ret;
 
+	paramBuffers_.clear();
+	statBuffers_.clear();
+
 	ret = output_->releaseBuffers();
 	if (ret)
 		LOG(IPU3, Error) << "Failed to release ImgU output buffers";

src/libcamera/pipeline/ipu3/imgu.h

@@ -76,6 +76,9 @@ public:
 	std::unique_ptr<V4L2VideoDevice> viewfinder_;
 	std::unique_ptr<V4L2VideoDevice> stat_;
 
+	std::vector<std::unique_ptr<FrameBuffer>> paramBuffers_;
+	std::vector<std::unique_ptr<FrameBuffer>> statBuffers_;
+
 private:
 	static constexpr unsigned int PAD_INPUT = 0;
 	static constexpr unsigned int PAD_PARAM = 1;