linux.git/include/media/media-entity.h, branch v6.0.6

media: mc-entity: Add a new helper function to get a remote pad for a pad

2022-07-17T10:23:51+00:00

The newly added media_entity_remote_source_pad_unique() helper function
handles use cases where the entity has a link enabled uniqueness
constraint covering all pads. There are use cases where the constraint
covers a specific pad only. Add a new media_pad_remote_pad_unique()
function to handle this. It operates as
media_entity_remote_source_pad_unique(), but on a given pad instead of
on the entity.

Signed-off-by: Laurent Pinchart 
Acked-by: Hans Verkuil 
Acked-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab

media: mc-entity: Add a new helper function to get a remote pad

2022-07-17T10:23:10+00:00

The media_entity_remote_pad_first() helper function returns the first
remote pad it finds connected to a given pad. Beside being possibly
non-deterministic (as it stops at the first enabled link), the fact that
it returns the first match makes it unsuitable for drivers that need to
guarantee that a single link is enabled, for instance when an entity can
process data from one of multiple sources at a time.

For those use cases, add a new helper function,
media_entity_remote_pad_unique(), that operates on an entity and returns
a remote pad, with a guarantee that only one link is enabled. To ease
its use in drivers, also add an inline wrapper that locates source pads
specifically. A wrapper that locates sink pads can easily be added when
needed.

Signed-off-by: Laurent Pinchart 
Acked-by: Hans Verkuil 
Acked-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab

media: mc-entity: Rename media_entity_remote_pad() to media_pad_remote_pad_first()

2022-07-17T10:21:35+00:00

The media_entity_remote_pad() is misnamed, as it operates on a pad and
not an entity. Rename it to media_pad_remote_pad_first() to clarify its
behaviour.

Signed-off-by: Laurent Pinchart 
Reviewed-by: Hans Verkuil 
Acked-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab

media: entity: Add iterator for entity data links

2022-07-15T14:24:40+00:00

Iterating over the links for an entity is a somewhat common need
through the media subsystem, but generally the assumption is that
they will all be data links. To meet that assumption add a new macro
that iterates through an entity's links and skips non-data links.

Signed-off-by: Daniel Scally 
Reviewed-by: Laurent Pinchart 
Signed-off-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab

media: media-entity.h: Fix documentation for media_create_intf_link

2022-04-24T07:28:16+00:00

The documentation comment was inserted between the return type
and the function name. Reunite the lines.

Signed-off-by: Ian Jamison 
Fixes: db7ee32aa185 ("[media] media-device.h: Improve documentation and update it")
Reviewed-by: Kieran Bingham 
Reviewed-by: Laurent Pinchart 
Signed-off-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab

media: entity: Add support for ancillary links

2022-04-24T06:59:09+00:00

Add functions to create ancillary links, so that they don't need to
be manually created by users.

Reviewed-by: Laurent Pinchart 
Signed-off-by: Daniel Scally 
Reviewed-by: Jean-Michel Hautbois 
Signed-off-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab

media: media-entity: Clarify media_entity_cleanup() usage

2022-03-03T22:27:09+00:00

Being able to call cleanup functions on objects that haven't been
initialized but whose memory has been zeroed simplifies error handling.
The media_entity_cleanup() function documentation doesn't tell whether
this is allowed or not, and inspection of its implementation doesn't
provide any clue as the function is currently empty. Update the
documentation to explicitly allow this usage pattern.

Signed-off-by: Laurent Pinchart 
Signed-off-by: Sakari Ailus

media: media-entity: Simplify media_pipeline_start()

2022-03-03T22:27:06+00:00

The media_pipeline_start() function has two purposes: it constructs a
pipeline by recording the entities that are part of it, gathered from a
graph walk, and validate the media links. The pipeline pointer is stored
in the media_entity structure as part of this process, and the entity's
stream count is increased, to record that the entity is streaming.

When multiple video nodes are present in a pipeline,
media_pipeline_start() is typically called on all of them, with the same
pipeline pointer. This is taken into account in media_pipeline_start()
by skipping validation for entities that are already part of the
pipeline, while returning an error if an entity is part of a different
pipeline.

It turns out that this process is overly complicated. When
media_pipeline_start() is called for the first time, it constructs the
full pipeline, adding all entities and validating all the links.
Subsequent calls to media_pipeline_start() are then nearly no-ops, they
only increase the stream count on the pipeline and on all entities.

The media_entity stream_count field is used for two purposes: checking
if the entity is streaming, and detecting when a call to
media_pipeline_stop() balances needs to reset the entity pipe pointer to
NULL. The former can easily be replaced by a check of the pipe pointer.

Simplify media_pipeline_start() by avoiding the pipeline walk on all
calls but the first one, and drop the media_entity stream_count field.
media_pipeline_stop() is updated accordingly.

Signed-off-by: Laurent Pinchart 
[Sakari Ailus: Drop redundant '!= NULL' as discussed]
Signed-off-by: Sakari Ailus

media: media-entity: Add media_pad_is_streaming() helper function

2022-03-03T22:27:06+00:00

Add a function to test if a pad is part of a pipeline currently
streaming, and use it through drivers to replace direct access to the
stream_count field. This will help reworking pipeline start/stop without
disturbing drivers.

Signed-off-by: Laurent Pinchart 
Signed-off-by: Sakari Ailus

include/media/media-entity.h: replace kernel.h with the necessary inclusions

2021-11-09T18:02:49+00:00

When kernel.h is used in the headers it adds a lot into dependency hell,
especially when there are circular dependencies are involved.

Replace kernel.h inclusion with the list of what is really being used.

Link: https://lkml.kernel.org/r/20211013170417.87909-8-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko 
Acked-by: Sakari Ailus 
Cc: Boqun Feng 
Cc: Brendan Higgins 
Cc: Ingo Molnar 
Cc: Jonathan Cameron 
Cc: Laurent Pinchart 
Cc: Mauro Carvalho Chehab 
Cc: Miguel Ojeda 
Cc: Peter Zijlstra 
Cc: Rasmus Villemoes 
Cc: Thomas Gleixner 
Cc: Thorsten Leemhuis 
Cc: Waiman Long 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds