[PATCH 00/13] Streaming control for MC with metadata or streams otherwise

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Hi all,

Starting and stopping streaming is a non-trivial problem in all but most
simple cases where there's only one stream. But when multiple streams come
into play, the problem quickly gets difficult to solve properly as it
generally spans multiple hardware deveices, not only including
transmitters (e.g. camera sensors) and receivers but also devices in
between, such as CSI-2 aggregators and serdes devices.

The following document summarises the known use cases:
<URL:https://pilvi.retiisi.eu/s/44RWYjKG92R6X49>, please let me know if
you have something to add that's not included here.

What this patchset implements is a partial solution, but it's also a
solution that can be extended to cover the above cases with relatively
small amendments.

The current functionality is best documented in patch "media: v4l2-mc:
Introduce v4l2_mc_pipeline_enabled()".

This set, in some form, is also effectively required by metadata support
patchset of which I'm about to post a new version. Starting per VC (for
CSI-2) is next on my to-do list when it comes to this set.

Getting these both in for 6.18 would be great.

Comments are very welcome.

Sakari Ailus (13):
  media: ipu6: Use correct pads for xlate_streams()
  media: ipu6: Set minimum height to 1
  media: ipu6: Enable and disable each stream at CSI-2 subdev source pad
  media: v4l2-subdev: Add a helper to figure out the pad streaming state
  media: v4l: Make media_entity_to_video_device() NULL-safe
  media: v4l2-subdev: Mark both streams of a route enabled
  media: ipu6: Set up CSI-2 receiver at correct moment
  media: v4l2-subdev: Print early in
    v4l2_subdev_{enable,disable}_streams()
  media: v4l2-subdev: Collect streams on source pads only
  media: v4l2-subdev: Add debug prints to v4l2_subdev_collect_streams()
  media: v4l2-subdev: Introduce v4l2_subdev_find_route()
  media: v4l2-mc: Introduce v4l2_mc_pipeline_enabled()
  media: ipu6: isys: Rework stream starting and stopping

 drivers/media/pci/intel/ipu6/ipu6-isys-csi2.c |  63 +++--
 .../media/pci/intel/ipu6/ipu6-isys-queue.c    |  48 ++--
 .../media/pci/intel/ipu6/ipu6-isys-video.c    |  96 ++++---
 .../media/pci/intel/ipu6/ipu6-isys-video.h    |   9 +-
 drivers/media/pci/intel/ipu6/ipu6-isys.h      |   2 +-
 drivers/media/v4l2-core/v4l2-mc.c             | 243 ++++++++++++++++++
 drivers/media/v4l2-core/v4l2-subdev.c         | 107 +++++---
 include/media/v4l2-dev.h                      |  14 +-
 include/media/v4l2-mc.h                       |  44 ++++
 include/media/v4l2-subdev.h                   |  22 ++
 10 files changed, 539 insertions(+), 109 deletions(-)

-- 
2.39.5