18 Aug, 2013
1 commit
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The graph traversal API (media_entity_graph_walk_*) doesn't support
cyclic graphs and will fail to correctly walk a graph when circular
links exist. Support circular graph traversal by checking whether an
entity has already been visited before pushing it to the stack.Signed-off-by: Laurent Pinchart
Acked-by: Sakari Ailus
Acked-by: Hans Verkuil
Signed-off-by: Mauro Carvalho Chehab
19 Jun, 2013
1 commit
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This function allows to remove all media entity's links to other
entities, leaving no references to a media entity's links array
at its remote entities.
Currently, when a driver of some entity is removed it will free its
media entities links[] array, leaving dangling pointers at other
entities that are part of same media graph. This is troublesome when
drivers of a media device entities are in separate kernel modules,
removing only some modules will leave others in an incorrect state.
This function is intended to be used when an entity is being
unregistered from a media device.
With an assumption that normally the media links should be created
between media entities registered to a media device, with the graph
mutex held.Signed-off-by: Sylwester Nawrocki
Reviewed-by: Andrzej Hajda
Signed-off-by: Kyungmin Park
Acked-by: Laurent Pinchart
Acked-by: Sakari Ailus
Signed-off-by: Mauro Carvalho Chehab
13 Jun, 2013
1 commit
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Currently the media device link_notify callback is invoked before the
actual change of state of a link when the link is being enabled, and
after the actual change of state when the link is being disabled.
This doesn't allow a media device driver to perform any operations
on a full graph before a link is disabled, as well as performing
any tasks on a modified graph right after a link's state is changed.
This patch modifies signature of the link_notify callback. This
callback is now called always before and after a link's state change.
To distinguish the notifications a 'notification' argument is added
to the link_notify callback: MEDIA_DEV_NOTIFY_PRE_LINK_CH indicates
notification before link's state change and
MEDIA_DEV_NOTIFY_POST_LINK_CH corresponds to a notification after
link flags change.[mchehab@redhat.com: whitespace cleanups]
Signed-off-by: Sylwester Nawrocki
Signed-off-by: Kyungmin Park
Acked-by: Laurent Pinchart
Acked-by: Sakari AilusSigned-off-by: Mauro Carvalho Chehab
09 Jun, 2013
1 commit
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Function media_entity_remote_source actually returns the remote pad to
the given one, regardless if this is the source or the sink pad.
Name media_entity_remote_pad is more adequate for this function.Signed-off-by: Andrzej Hajda
Signed-off-by: Kyungmin Park
Acked-by: Sakari Ailus
Acked-by: Sylwester Nawrocki
Signed-off-by: Laurent Pinchart
Signed-off-by: Mauro Carvalho Chehab
14 May, 2012
1 commit
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The purpose of the link_validate() op is to allow an entity driver to ensure
that the properties of the pads at the both ends of the link are suitable
for starting the pipeline. link_validate is called on sink pads on active
links which belong to the active part of the graph.Signed-off-by: Sakari Ailus
Acked-by: Laurent Pinchart
Signed-off-by: Mauro Carvalho Chehab
17 Apr, 2011
1 commit
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The link flags were not properly handled in __media_entity_setup_link
which could lead to link_notify callback to be called when the flags are
not modified. Fix this.Signed-off-by: Laurent Pinchart
Signed-off-by: Mauro Carvalho Chehab
22 Mar, 2011
5 commits
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Drivers often need to associate pipeline objects to entities, and to
take stream state into account when configuring entities and links. The
pipeline API helps drivers manage that information.When starting streaming, drivers call media_entity_pipeline_start(). The
function marks all entities connected to the given entity through
enabled links, either directly or indirectly, as streaming. Similarly,
when stopping the stream, drivers call media_entity_pipeline_stop().The media_entity_pipeline_start() function takes a pointer to a media
pipeline and stores it in every entity in the graph. Drivers should
embed the media_pipeline structure in higher-level pipeline structures
and can then access the pipeline through the media_entity structure.Link configuration will fail with -EBUSY by default if either end of the
link is a streaming entity, unless the link is marked with the
MEDIA_LNK_FL_DYNAMIC flag.Signed-off-by: Laurent Pinchart
Acked-by: Hans Verkuil
Signed-off-by: Mauro Carvalho Chehab -
Create the following ioctl and implement it at the media device level to
setup links.- MEDIA_IOC_SETUP_LINK: Modify the properties of a given link
The only property that can currently be modified is the ENABLED link
flag to enable/disable a link. Links marked with the IMMUTABLE link flag
can not be enabled or disabled.Enabling or disabling a link has effects on entities' use count. Those
changes are automatically propagated through the graph.Signed-off-by: Laurent Pinchart
Signed-off-by: Stanimir Varbanov
Signed-off-by: Sakari Ailus
Acked-by: Hans Verkuil
Signed-off-by: Mauro Carvalho Chehab -
Due to the wide differences between drivers regarding power management
needs, the media controller does not implement power management.
However, the media_entity structure includes a use_count field that
media drivers can use to track the number of users of every entity for
power management needs.The use_count field is owned by media drivers and must not be touched by
entity drivers. Access to the field must be protected by the media
device graph_mutex lock.Signed-off-by: Laurent Pinchart
Acked-by: Hans Verkuil
Signed-off-by: Mauro Carvalho Chehab -
Add media entity graph traversal. The traversal follows enabled links by
depth first. Traversing graph backwards is prevented by comparing the next
possible entity in the graph with the previous one. Multiply connected
graphs are thus not supported.Signed-off-by: Sakari Ailus
Signed-off-by: Laurent Pinchart
Signed-off-by: Vimarsh Zutshi
Acked-by: Hans Verkuil
Signed-off-by: Mauro Carvalho Chehab -
As video hardware pipelines become increasingly complex and
configurable, the current hardware description through v4l2 subdevices
reaches its limits. In addition to enumerating and configuring
subdevices, video camera drivers need a way to discover and modify at
runtime how those subdevices are connected. This is done through new
elements called entities, pads and links.An entity is a basic media hardware building block. It can correspond to
a large variety of logical blocks such as physical hardware devices
(CMOS sensor for instance), logical hardware devices (a building block
in a System-on-Chip image processing pipeline), DMA channels or physical
connectors.A pad is a connection endpoint through which an entity can interact with
other entities. Data (not restricted to video) produced by an entity
flows from the entity's output to one or more entity inputs. Pads should
not be confused with physical pins at chip boundaries.A link is a point-to-point oriented connection between two pads, either
on the same entity or on different entities. Data flows from a source
pad to a sink pad.Links are stored in the source entity. To make backwards graph walk
faster, a copy of all links is also stored in the sink entity. The copy
is known as a backlink and is only used to help graph traversal.The entity API is made of three functions:
- media_entity_init() initializes an entity. The caller must provide an
array of pads as well as an estimated number of links. The links array
is allocated dynamically and will be reallocated if it grows beyond the
initial estimate.- media_entity_cleanup() frees resources allocated for an entity. It
must be called during the cleanup phase after unregistering the entity
and before freeing it.- media_entity_create_link() creates a link between two entities. An
entry in the link array of each entity is allocated and stores pointers
to source and sink pads.When a media device is unregistered, all its entities are unregistered
automatically.The code is based on Hans Verkuil initial work.
Signed-off-by: Laurent Pinchart
Signed-off-by: Sakari Ailus
Acked-by: Hans Verkuil
Signed-off-by: Mauro Carvalho Chehab