Initialise a given graph walk object once, and then keep using it whilst
the same pipeline is running. Once the pipeline is stopped, release the
graph walk object.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

This will also mean that the necessary graph related data structures will
be allocated dynamically, removing the need for maximum ID checks.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The media graph walk requires initialisation and cleanup soon. Update the
users to perform the soon necessary API calls.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The media graph walk requires initialisation and cleanup soon. Update the
users to perform the soon necessary API calls.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Cc: Hyun Kwon <hyun.kwon@xilinx.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The media graph walk requires initialisation and cleanup soon. Update the
users to perform the soon necessary API calls.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Cc: Javier Martinez Canillas <javier@osg.samsung.com>
Cc: Kamil Debski <k.debski@samsung.com>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The media graph walk requires initialisation and cleanup soon. Update the
users to perform the soon necessary API calls.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The media graph walk requires initialisation and cleanup soon. Update the
users to perform the soon necessary API calls.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Add media_entity_graph_walk_init() and media_entity_graph_walk_cleanup()
functions in order to dynamically allocate memory for the graph. This is
not done in media_entity_graph_walk_start() as there are situations where
e.g. correct error handling, that itself may not fail, requires successful
graph walk.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The struct media_entity_graph was allocated in the stack, limiting the
number of entities that could be reasonably allocated. Instead, move the
struct to struct media_pipeline which is typically allocated using
kmalloc() instead.

The intent is to keep the enumeration around for later use for the
duration of the streaming. As streaming is eventually stopped, an
unfortunate memory allocation failure would prevent stopping the
streaming. As no memory will need to be allocated, the problem is avoided
altogether.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

KernelDoc doesn't appear to handle anonymous structs defined inside
another gracefully. As the struct is internal to the framework graph walk
algorithm, detailed documentation isn't seen very important.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

It will be needed in struct media_pipeline shortly.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

This is useful in e.g. knowing whether certain operations have already
been performed for an entity. The users include the framework itself (for
graph walking) and a number of drivers.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The internal index can be used internally by the framework in order to keep
track of entities for a purpose or another. The internal index is constant
while it's registered to a media device, but the same index may be re-used
once the entity having that index is unregistered.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

We need to set "err = -ENOMEM" here.

Fixes: 38b11f19667a ('[media] v4l2-core: create MC interfaces for devnodes')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The copy_to/from_user() functions return the number of bytes *not*
copied.  They don't return error codes.

Fixes: 4f6b3f363475 ('media] media-device: add support for MEDIA_IOC_G_TOPOLOGY ioctl')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The G_TOPOLOGY ioctl is used to get a graph topology and since in the
future a graph can be dynamically updated, there is a way to know the
topology version so userspace can be aware that the graph has changed.

The version 0 is reserved to indicate that the graph is static (i.e no
graphs updates since the media device was registered).

So, now that the media device initialization and registration has been
split and the media device node is not exposed to user-space until all
the entities have been registered and links created, it is safe to set
a topology version 0 in media_device_register().
Suggested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Suggested-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Registering a V4L2 sub-device includes, among other things, registering
the related media entity and calling the sub-device's registered op. Since
patch "media: convert links from array to list", creating a link between
two pads requires registering the entity first. If the registered() op
involves link creation, the link list head will not be initialised before
it is used.

Resolve this by first registering the entity, then calling its
registered() op.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

There are now two new warnings:

drivers/media/usb/dvb-usb-v2/dvb_usb_core.c: In function 'dvb_usbv2_media_device_register':
drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:433:2: warning: ignoring return value of '__media_device_register', declared with attribute warn_unused_result [-Wunused-result]
  media_device_register(adap->dvb_adap.mdev);
  ^
drivers/media/usb/dvb-usb/dvb-usb-dvb.c: In function 'dvb_usb_media_device_register':
drivers/media/usb/dvb-usb/dvb-usb-dvb.c:128:2: warning: ignoring return value of '__media_device_register', declared with attribute warn_unused_result [-Wunused-result]
  media_device_register(adap->dvb_adap.mdev);
  ^

Those are because the drivers are not properly checking if the
media device init and register were succeeded.

Fix it.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The media device node is registered and so made visible to user-space
before entities are registered and links created which means that the
media graph obtained by user-space could be only partially enumerated
if that happens too early before all the graph has been created.

To avoid this race condition, split the media init and registration
in separate functions and only register the media device node when
all the pending subdevices have been registered, either explicitly
by the driver or asynchronously using v4l2_async_register_subdev().

The media_device_register() had a check for drivers not filling dev
and model fields but all drivers in mainline set them and not doing
it will be a driver bug so change the function return to void and
add a BUG_ON() for dev being NULL instead.

Also, add a media_device_cleanup() function that will destroy the
graph_mutex that is initialized in media_device_init().

[mchehab@osg.samsung.com: Fix compilation if !CONFIG_MEDIA_CONTROLLER
 and remove two warnings added by this changeset]
Suggested-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

If media_device_unregister() is called by two different
drivers, a race condition may happen, as the check if the
device is not registered is not protected.

Move the spin_lock() to happen earlier in the function, in order
to prevent such race condition.
Reported-by: NShuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

media entity register and unregister functions are called by media
device register/unregister. Move them to occur earlier, as we'll need
an unlocked version of media_device_entity_unregister() and we don't
want to add a function prototype without needing it.

No functional changes.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Most media functions that unregister, check if the corresponding register
function succeed before. So these functions can safely be called even if a
registration was never made or the component as already been unregistered.

Add the same check to media_device_unregister() function for consistency.

This will also allow to split the media_device_register() function in an
initialization and registration functions without the need to change the
generic cleanup functions and error code paths for all the media drivers.
Suggested-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

As pointed by Dan, the commit f8fd4c61b5ae ("[media] media-entity:
protect object creation/removal using spin lock")' leads to the
following static checker warning:

	drivers/media/media-entity.c:781 media_remove_intf_link()
	error: dereferencing freed memory 'link'

drivers/media/media-entity.c
   777  void media_remove_intf_link(struct media_link *link)
   778  {
   779          spin_lock(&link->graph_obj.mdev->lock);
   780          __media_remove_intf_link(link);
   781          spin_unlock(&link->graph_obj.mdev->lock);

In practice, I didn't see any troubles even with KASAN enabled. I guess
gcc optimizer internally cached the mdev reference, instead of getting
it twice. Yet, it is a very bad idea to rely on such optimization. So,
let's fix the code.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Changeset f8fd4c61b5ae ("[media] media-entity: protect object
creation/removal using spin lock") changed the object creation/removal
protection to spin lock, as this is what's used on media-device,
keeping the mutex reserved for graph traversal routines. However, it
also changed the link setup, by mistake.

This could cause troubles, as the link setup can affect the graph
traversal, and this is likely the reason for a mutex there.

So, revert media_entity_setup_link() to use mutex.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

There is one struct and two functions that were not documented.
Add the corresponding kernel-doc documentation for them.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

As we're using the headers file only for documentation, move the
two kernel-doc macros to the header, and fix it to avoid
warnings.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Add kernel-doc documentation for media_device_get_devres and
media_device_find_devres.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Add a basic documentation for most ancillary functions.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

If a different entity->pipe in a pipeline was encountered, a warning was
issued but the execution continued as if nothing had happened. Return an
error instead right there.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Add description for this new media controller ioctl.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Document the media controller interfaces at the media
uAPI docbook.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

There were some changes on the media types that were not reflected
on the types tables. Update them to reflect the upstream changes.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

As MEDIA_IOC_G_TOPOLOGY shares the data types already declared
for entities, pads and links, we should move those to a separate
part of the document, and use cross-references where needed.

So, move the following tables to a separate section at the
DocBook:
	media-entity-type
	media-entity-flag
	media-pad-flag
	media-link-flag
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The Media Controller next generation patches added a new graph
element type: interfaces. It also allows links between interfaces
and entities. Update the docbook to reflect that.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The Media Controller next gen patchset added several new fields
to be used with it. Document them.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The V4L2 core won't be adding connectors to the tuners and other
entities that need them. Let it be clear.
Suggested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Instead of flagging an interface link as MEDIA_LNK_FL_INTERFACE_LINK
only when returning to userspace, do it at link creation time.

That would allow using such flag internally, and cleans up a
little bit the code for G_TOPOLOGY ioctl.

[mchehab@osg.samsung.com: folded with a fixup from Dan Carpenter,
 replacing & by &&]
Suggested-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Commit 86ee417578a2 ("[media] media: convert links from array to list")
had many changes that were automated using coccinelle but the semantic
patch was not smart enough to rely on operators precedence and avoid
using unnecessary enclosing parenthesis.

This patch removes them since are not needed.
Suggested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The uvc_mc_register_entities() function iterated over the entities three
times to initialize the entities, register the subdev for the ones whose
type was UVC_TT_STREAMING and to create the entities links.

But this can be simplied by merging the init and registration logic in a
single loop.
Suggested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The function uvc_mc_create_pads_links() creates entities links but the
"pads" prefix is redundant since the driver doesn't handle any other
kind of link, so it can be removed.
Suggested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>