[libcamera-devel] [PATCH v2 00/13] libcamera: ipu3: Refactoring of ImgU

[Tomasz Figa]

Hi Niklas and everyone,

On Sun, Jun 28, 2020 at 2:15 AM Niklas Söderlund
<niklas.soderlund at ragnatech.se> wrote:
>
> Hi,
>
> This series do some cleanup of the IPU3 pipeline. It removes dead or
> almost dead code, replacing it with something more coherent to what is
> done elsewhere in the pipeline. It breaks out the ImgU to a separate cpp
> and h file.
>
> It reworks a bit how the streams are identified and handled inside the
> pipeline. When the pipeline was first developed only the output and
> viewfinder streams where available, now we have a RAW stream in addition
> to this. Some of the abstraction around streams and which hardware
> resource they are backed by made sens in the earlier context but not so
> much once RAW is added to the mix. The biggest difference in this rework
> is that the ImgUDevice gets explicit functions to configure each of its
> sink instead of having a generic one which depends which pointer is
> passed to it. This makes reading code where RAW and ImgU streams are
> mixed much nicer IMHO.

CIO2 is quite a generic capture interface, which could be handled by
some platform-independent code. Have we considered splitting the
pipeline into a generic capture part and platform-specific processing
part? I think it could be useful on its own, as the capture part of
all the SoCs could be handled by generic code, but I also suspect that
the ability to split the pipeline into multiple smaller pipelines and
then join them together could be very useful when dealing with many
SoC generations, since vendors quite often replace some parts of the
pipeline with new hardware, while keeping the others unchanged.

What do you think?

Best regards,
Tomasz

>
> Lastly some assumptions that buffers must be allocated at video nodes
> that are not involved in the capture session are being challenged. This
> was true a year ago but not any more it seems. Chancing this simplifies
> the driver enormously and saves on memory that otherwise would be
> wasted. I have really tried to force the end result to failed by
> resetting the hardware between each test so that no video node
> configuration from a previous sessions saves the day.
>
> I have for both sensors reset the hardware and then tested the following
> capture combinations successfully. After the first capture session for
> each one in the list that was done after a power cycle all the other
> captures where tried in a semi random order and always succeeded.
>
>   cam -c 1 -s role=viewfinder -C
>   cam -c 1 -s role=still  -C
>   cam -c 1 -s role=still -s role=viewfinder -C
>   cam -c 1 -s role=still -s role=viewfinder -s role=stillraw -C
>   cam -c 1 -s role=stillraw -C
>
> Niklas Söderlund (13):
>   libcamera: ipu3: Remove unused name_ filed from IPU3Stream
>   libcamera: ipu3: Import instead of allocate statistic buffers
>   libcamera: ipu3: Always import buffers for ImgU sinks
>   libcamera: ipu3: Remove usage of IPU3CameraData from ImgUDevice
>   libcamera: ipu3: imgu: Move the ImgUDevice class to separate files
>   libcamera: ipu3: imgu: Do not cache index
>   libcamera: ipu3: imgu: Mark things that are internal as private
>   libcamera: ipu3: imgu: Use specific functions to configure each sink
>   libcamera: ipu3: Do not duplicate data in IPU3Stream
>   libcamera: ipu3: Remove the active flag from IPU3Stream
>   libcamera: ipu3: Remove IPU3Stream
>   libcamera: ipu3: imgu: Remove ImgUOutput
>   libcamera: ipu3: imgu: Use unique_ptr for video and subdevices
>
>  src/libcamera/pipeline/ipu3/imgu.cpp    | 353 +++++++++++++++
>  src/libcamera/pipeline/ipu3/imgu.h      |  87 ++++
>  src/libcamera/pipeline/ipu3/ipu3.cpp    | 548 +++---------------------
>  src/libcamera/pipeline/ipu3/meson.build |   1 +
>  4 files changed, 505 insertions(+), 484 deletions(-)
>  create mode 100644 src/libcamera/pipeline/ipu3/imgu.cpp
>  create mode 100644 src/libcamera/pipeline/ipu3/imgu.h
>
> --
> 2.27.0
>
> _______________________________________________
> libcamera-devel mailing list
> libcamera-devel at lists.libcamera.org
> https://lists.libcamera.org/listinfo/libcamera-devel