linux-stable.git/drivers/media/mc, branch v6.3

media: mc: entity: Fix minor issues in comments and documentation

2023-02-06T07:37:12+00:00

Commit ae219872834a ("media: mc: entity: Rewrite
media_pipeline_start()") incorrectly referred to entity instead of pad
in a comment, and forgot to update a second comment accordingly when
moving the pipe from entity to pad. Furthermore, it didn't properly
reflow the documentation text it updated.

Fix those small issues.

Fixes: ae219872834a ("media: mc: entity: Rewrite media_pipeline_start()")
Signed-off-by: Laurent Pinchart 
Reviewed-by: Tomi Valkeinen 
Signed-off-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab

media: mc: Get media_device directly from pad

2023-02-06T07:36:42+00:00

Various functions access the media_device from a pad by going through
the entity the pad belongs to. Remove the level of indirection and get
the media_device from the pad directly.

Fixes: 9e3576a1ae2b ("media: mc: convert pipeline funcs to take media_pad")
Signed-off-by: Laurent Pinchart 
Reviewed-by: Tomi Valkeinen 
Signed-off-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab

media: mc: entity: Add entity iterator for media_pipeline

2023-02-06T07:33:44+00:00

Add a media_pipeline_for_each_entity() macro to iterate over entities in
a pipeline. This should be used by driver as a replacement of the
media_graph_walk API, as iterating over the media_pipeline uses the
cached list of pads and is thus more efficient.

Deprecate the media_graph_walk API to indicate it shouldn't be used in
new drivers.

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

media: mc: entity: Add pad iterator for media_pipeline

2023-02-06T07:31:51+00:00

Add a media_pipeline_for_each_pad() macro to iterate over pads in a
pipeline. This should be used by driver as a replacement of the
media_graph_walk API, as iterating over the media_pipeline uses the
cached list of pads and is thus more efficient.

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

media: mc: entity: Fix doc for media_graph_walk_init

2023-01-22T08:25:29+00:00

There is no media_graph_walk_free(). media_graph_walk_cleanup() is used
to release the resources.

Signed-off-by: Miaoqian Lin 
Signed-off-by: Laurent Pinchart 
Signed-off-by: Mauro Carvalho Chehab

media: mc: Improve the media_entity_has_pad_interdep() documentation

2023-01-22T08:25:11+00:00

Document the function parameters, the requirements on the pad0 and pad1
arguments, the locking requirements and the return value. Also improve
the documentation of the corresponding .has_pad_interdep() operation,
stating clearly that the operation must be called through the
media_entity_has_pad_interdep() function only.

Signed-off-by: Laurent Pinchart 
Reviewed-by: Tomi Valkeinen 
Signed-off-by: Mauro Carvalho Chehab

media: mc: convert pipeline funcs to take media_pad

2022-09-24T07:22:30+00:00

Now that the pipeline is stored into pads instead of entities, we can
change the relevant functions to take pads instead of entities.

Signed-off-by: Tomi Valkeinen 
Reviewed-by: Laurent Pinchart 
Signed-off-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab

media: mc: entity: Add has_pad_interdep entity operation

2022-09-24T07:20:30+00:00

Add a new media entity operation, has_pad_interdep. The optional op is
used to discover the pad interdependencies inside an entity during the
pipeline construction.

Signed-off-by: Tomi Valkeinen 
Signed-off-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab

media: mc: entity: Rewrite media_pipeline_start()

2022-09-24T07:19:42+00:00

[Note: the code is mostly from Laurent but the patch description is from Tomi]

The media_pipeline_start() and media_pipeline_stop() functions use the
media graph walk API to traverse the graph and validate the pipeline.
The graph walk traverses the media graph following links between the
entities.

Also, while the pipeline can't change between the start and stop calls,
the graph is walked again from scratch at stop time, or any time a
driver needs to inspect the pipeline.

With the upcoming multiplexed streams support we will need a bit more
intelligent pipeline construction, as e.g. two independent streams may
be passing through a single entity via separate pads in which case
those pads should not be part of the same pipeline.

This patch essentially rewrites the media_pipeline_start/stop so that
a pipeline is defined as a set of pads instead of entities and the media
graph traversal considers the pad interdependencies when choosing which
links to follow.

Currently all the entity's pads are considered as interdependent. This
means that the behavior with all the current drivers stays the same, but
in the future we can define a more fine-grained pipeline construction.

Additionally the media pipeline's pads are cached at
media_pipeline_start() time, and re-used at media_pipeline_stop() which
avoid the need to re-walk the whole graph as the previous implementation
did.

Also, caching pads in the pipeline can serve in the future as the
foundation to provide a better API than the media graph walk to drivers
to iterate over pads and entities in the pipeline.

Note that the old media_pipeline_start/stop used the media graph walk
API. The new version does not use the media graph walk API, but instead
a new implementation.

There are two reasons for not changing the graph walk: it proved to be
rather difficult to change the graph walk to have the features
implemented in this patch, and second, this keeps the backward
compatibility of the graph walk as there are users of the graph walk API

The long term plan is that all the existing code would be converted to
use the new cached pipeline, thus allowing us to remove the graph walk.

Signed-off-by: Laurent Pinchart 
Signed-off-by: Tomi Valkeinen 
Signed-off-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab

media: mc: entity: add alloc variant of pipeline_start

2022-09-24T07:15:52+00:00

Add new variant of media_pipeline_start(), media_pipeline_alloc_start().

media_pipeline_alloc_start() can be used by drivers that do not need to
extend the media_pipeline. The function will either use the pipeline
already associated with the entity, if such exists, or allocate a new
pipeline.

When media_pipeline_stop() is called and the pipeline's use count drops
to zero, the pipeline is automatically freed.

Signed-off-by: Tomi Valkeinen 
Reviewed-by: Laurent Pinchart 
Signed-off-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab