[libcamera-devel] [PATCH 2/4] libcamera: pipeline: vimc: Propagate media bus format

[Laurent Pinchart]

Hi Niklas,

Thank you for the patch.

On Mon, Aug 05, 2019 at 05:51:31PM +0200, Niklas Söderlund wrote:
> Linux commit 85ab1aa1fac17bcd ("media: vimc: deb: fix default sink bayer
> format") which is part of v5.2 changes the default media bus format for
> the debayer subdevices. This leads to a -EPIPE error when trying to use
> the raw capture video device nodes.
> 
> Fix this by propagating the media bus format used on the debayer
> subdevcie to the sensor. This allows the same code to function on
> kernels previous to the change and after it.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> ---
>  src/libcamera/pipeline/vimc.cpp | 21 ++++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/src/libcamera/pipeline/vimc.cpp b/src/libcamera/pipeline/vimc.cpp
> index 3d6808222a8a2c5d..ae612b48436d1164 100644
> --- a/src/libcamera/pipeline/vimc.cpp
> +++ b/src/libcamera/pipeline/vimc.cpp
> @@ -25,6 +25,7 @@
>  #include "pipeline_handler.h"
>  #include "utils.h"
>  #include "v4l2_controls.h"
> +#include "v4l2_subdevice.h"
>  #include "v4l2_videodevice.h"
>  
>  namespace libcamera {
> @@ -35,13 +36,15 @@ class VimcCameraData : public CameraData
>  {
>  public:
>  	VimcCameraData(PipelineHandler *pipe)
> -		: CameraData(pipe), video_(nullptr), sensor_(nullptr)
> +		: CameraData(pipe), video_(nullptr), debayer_(nullptr),
> +		  sensor_(nullptr)
>  	{
>  	}
>  
>  	~VimcCameraData()
>  	{
>  		delete sensor_;
> +		delete debayer_;
>  		delete video_;
>  	}
>  
> @@ -49,6 +52,7 @@ public:
>  	void bufferReady(Buffer *buffer);
>  
>  	V4L2VideoDevice *video_;
> +	V4L2Subdevice *debayer_;
>  	CameraSensor *sensor_;
>  	Stream stream_;
>  };
> @@ -188,6 +192,17 @@ int PipelineHandlerVimc::configure(Camera *camera, CameraConfiguration *config)
>  	    format.fourcc != cfg.pixelFormat)
>  		return -EINVAL;
>  
> +	V4L2SubdeviceFormat subformat = {};
> +	subformat.size = cfg.size;
> +
> +	ret = data->debayer_->setFormat(0, &subformat);
> +	if (ret)
> +		return ret;
> +
> +	ret = data->sensor_->setFormat(&subformat);
> +	if (ret)
> +		return ret;

The sensor comes before the debayering subdevice, shouldn't you set the
format on the sensor first ? That may require setting the bus format in
subformat, but I think you can simply hardcode that. I would also
configure this before configuring the video node.

> +
>  	cfg.setStream(&data->stream_);
>  
>  	return 0;
> @@ -340,6 +355,10 @@ int VimcCameraData::init(MediaDevice *media)
>  	if (video_->open())
>  		return -ENODEV;
>  
> +	debayer_ = new V4L2Subdevice(media->getEntityByName("Debayer B"));
> +	if (debayer_->open())
> +		return -ENODEV;
> +
>  	video_->bufferReady.connect(this, &VimcCameraData::bufferReady);
>  
>  	sensor_ = new CameraSensor(media->getEntityByName("Sensor B"));

-- 
Regards,

Laurent Pinchart