[libcamera-devel] [PATCH 05/10] libcamera: ipu3: Calculate number of buffers for ImgU

[Niklas Söderlund]

Decouple the number of buffers to allocate for the ImgU from the number
of buffers allocated for the CIO2. Instead of blindly following the CIO2
pick the maximum number of buffers requested for any stream facing
applications.

This is potentially wasteful, as each stream could allocate just as many
buffers as requested by the application instead of the maximum from the
set. But this is not more wasteful then whats already used by the
pipeline and should be fixed on top after the decoupling of the two
processing units.

Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
 src/libcamera/pipeline/ipu3/ipu3.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
index 0e7555c716b36749..f4759715c6ae7572 100644
--- a/src/libcamera/pipeline/ipu3/ipu3.cpp
+++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
@@ -729,14 +729,16 @@ int PipelineHandlerIPU3::allocateBuffers(Camera *camera)
 	IPU3CameraData *data = cameraData(camera);
 	CIO2Device *cio2 = &data->cio2_;
 	ImgUDevice *imgu = data->imgu_;
-	unsigned int bufferCount;
+	unsigned int bufferCount = 0;
 	int ret;
 
 	ret = cio2->allocateBuffers();
 	if (ret < 0)
 		return ret;
 
-	bufferCount = ret;
+	bufferCount = std::max<unsigned int>(data->outStream_.configuration().bufferCount, bufferCount);
+	bufferCount = std::max<unsigned int>(data->vfStream_.configuration().bufferCount, bufferCount);
+	bufferCount = std::max<unsigned int>(data->rawStream_.configuration().bufferCount, bufferCount);
 
 	ret = imgu->allocateBuffers(data, bufferCount);
 	if (ret < 0) {
-- 
2.26.2