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: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro 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: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Mauro 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: Mauro 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: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro 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: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro 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: Mauro 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: Mauro 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: Mauro 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: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro 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: Mauro 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: Mauro 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: Mauro 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: Mauro 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: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro 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: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro 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: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro 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: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro 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: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro 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: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro 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: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro 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: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Javier Martinez Canillas
Mauro Carvalho Chehab
Sakari Ailus