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>

The for loop in the vsp1_create_entities() function that create the links,
checks the entity type and call the proper link creation function but then
it uses continue to force the next iteration of the loop to take place and
skipping code in between that creates links for different entities types.

It is more readable and easier to understand if the if else constructs is
used instead of the continue statement.
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 functions that create entities links are called *_create_pads_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>

The functions that create ISS internal and external entities links are
called *_create_pads_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>

The isp_subdev_notifier_complete() complete callback defines a struct
v4l2_device *v4l2_dev to avoid needing two level of indirections to
access the V4L2 subdevs but the var is not always used when possible
as when calling v4l2_device_register_subdev_nodes().

So change that to consistently use the defined v4l2_dev pointer var.
Suggested-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Commit bc36b30fe06b ("[media] omap3isp: separate links creation from
entities init") moved the link creation logic from the entities init
functions and so removed the error_link labels from the error paths.

But after that, some functions have a single error label so it makes
more sense to rename the label to just "error" in thi case.
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 that creates the links between ISP internal and external
entities is called isp_create_pads_links() but the "pads" prefix is
redundant since the driver doesn't handle any other kind of link so
it can just be removed.

While being there, fix the function's kernel-doc since is not using
a proper format.
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 entities to video nodes links were created on separate functions for
each ISP module but since the only thing that these functions do is to
call media_create_pad_link(), there's no need for that indirection level
and all link creation logic can be just inlined in the caller function.

Also, since the only possible failure for the link creation is a memory
allocation, there is no need for error messages since the core already
reports a very verbose message in that case.
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>

By using u64 integers and pointers, we can get rid of compat32
logic. So, let's do it!
Suggested-by: NArnd Bergmann <arnd@arndb.de>
Suggested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Improve the documentation to let it clear that the entity function
must be initialized.
Suggested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The pad index is unsigned. Replace the occurences of it where
pertinent.
Suggested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Several additional functions are described at media-entity.c.
Moving them to the header file, to make the code cleaner and
to have all such macros at the same place.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Those media_obj_* functions are actually creating/destroying
media graph objects. So, rename them to better represent
what they're actually doing.

No functional changes.

This was created via this small shell script:

	for i in $(git grep -l media_gobj_init); do sed s,media_gobj_init,media_gobj_create,g <$i >a && mv a $i; done
	for i in $(git grep -l media_gobj_remove); do sed s,media_gobj_remove,media_gobj_destroy,g <$i >a && mv a $i; done
Suggested-by: NSakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

> > > +		if (rlink != link->reverse) {
> > > +			r++;
> >
> > The variable is incremented here but otherwise never used, you can remove it.
Suggested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>