Drivers might try to access and run enable_source and disable_source
handlers when the driver that implements these handlers is clearing
the handlers during its unregister.
Fix the following race condition:
process 1 process 2
request video streaming unbind au0828
v4l2 checks if tuner is free
... ...
au0828_unregister_media_device()
... ...
(doesn't hold graph_mutex)
mdev->enable_source = NULL;
if (mdev && mdev->enable_source) mdev->disable_source = NULL;
mdev->enable_source()
(enable_source holds graph_mutex)
As shown above enable_source check is done without holding the graph_mutex.
If unbind happens to be in progress, au0828 could clear enable_source and
disable_source handlers leading to null pointer de-reference.
Fix it by protecting enable_source and disable_source set and clear and
protecting enable_source and disable_source handler access and the call
itself.
process 1 process 2
request video streaming unbind au0828
v4l2 checks if tuner is free
... ...
au0828_unregister_media_device()
... ...
(hold graph_mutex while clearing)
mdev->enable_source = NULL;
if (mdev) mdev->disable_source = NULL;
(hold graph_mutex to check and
call enable_source)
if (mdev->enable_source)
mdev->enable_source()
If graph_mutex is held to just heck for handler being null and needs to be
released before calling the handler, there will be another window for the
handlers to be cleared. Hence, enable_source and disable_source handlers
no longer hold the graph_mutex and expect callers to hold it to avoid
forcing them release the graph_mutex before calling the handlers.
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
The media_entity_pipeline_start() and media_entity_pipeline_stop()
functions are renamed as media_pipeline_start() and media_pipeline_stop(),
respectively. The reason is two-fold: the pipeline struct is, rightly,
already called media_pipeline (rather than media_entity_pipeline) and what
this really is about is a pipeline. A pipeline consists of entities ---
and, well, other objects embedded in these entities.
As the pipeline object will be in the future moved from entities to pads
in order to support multiple pipelines through a single entity, do the
renaming now.
Similarly, functions operating on struct media_entity_graph as well as the
struct itself are renamed by dropping the "entity_" part from the prefix
of the function family and the data structure. The graph traversal which
is what the functions are about is not specifically about entities only
and will operate on pads for the same reason as the media pipeline.
The patch has been generated using the following command:
git grep -l media_entity |xargs perl -i -pe '
s/media_entity_pipeline/media_pipeline/g;
s/media_entity_graph/media_graph/g'
And a few manual edits related to line start alignment and line wrapping.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
For the third time in three years, I'm changing my e-mail at Samsung.
That's bad, as it may stop communications with me for a while. So, this
time, I'll also add the mchehab@kernel.org e-mail, as it remains stable
since ever.
Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All users of is_media_entity_v4l2_io() (the exynos4-is, omap3isp,
davince_vpfe and omap4iss drivers and the v4l2-mc power management code)
use the function to check whether entities are video_device instances,
either to ensure they can cast the entity to a struct video_device, or
to count the number of video nodes users.
The purpose of the function is thus to identify whether the media entity
instance is an instance of the video_device object, not to check whether
it can perform I/O. Rename it accordingly, we will introduce a more
specific is_media_entity_v4l2_io() check when needed.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Commit 840f5b0572 ("media: au0828 disable tuner to demod link in
au0828_media_device_register()") removed all uses of the 'dtv_demod',
but left the variable itself around.
Remove it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Disable tuner to demod link in au0828_media_device_register(). This step
should be done after dvb graph is created.
[mchehab@osg.samsung.com: Solve conflictst to apply it upstream]
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
When the Media controller framework was merged, it was decided not to add
pipeline power management code for it was not seen generic. As a result, a
number of drivers have copied the same piece of code, with same bugfixes
done to them at different points of time (or not at all).
Add these functions to V4L2. Their use is optional for drivers.
[mchehab@osg.samsung.com: Fix merge conflicts]
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
There's no reason to implement its own function to create the
media graph. So, use the core one.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Add a new interfaces to be used by v4l-core to invoke enable
source and disable_source handlers in the media_device. The
enable_source helper function invokes the enable_source handler
to find media source entity connected to the entity and check
is it is available or busy. If source is available, link is
activated and pipeline is started. The disable_source helper
function invokes the disable_source handler to deactivate and
stop the pipeline.
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Those ancillary functions could be called even when compiled
without V4L2 support, as warned by ktest build robot:
All errors (new ones prefixed by >>):
>> ERROR: "__v4l2_mc_usb_media_device_init" [drivers/media/usb/dvb-usb/dvb-usb.ko] undefined!
>> ERROR: "__v4l2_mc_usb_media_device_init" [drivers/media/usb/dvb-usb-v2/dvb_usb_v2.ko] undefined!
>> ERROR: "__v4l2_mc_usb_media_device_init" [drivers/media/usb/au0828/au0828.ko] undefined!
Also, there's nothing there that are specific to V4L2. So, move
those ancillary functions to MC core.
No functional changes. Just function rename.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
It should be a bitwise or, and not a logical one. Also, add
parenthesis, to make sure it will be applied in the right order.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This fixes this warning:
v4l2-mc.c: In function 'v4l2_mc_create_media_graph':
v4l2-mc.c:60:69: warning: variable 'sensor' set but not used [-Wunused-but-set-variable]
We could solve it the other way: don't do the second loop for
webcams. However, that would fail if a chip would have two sensors
plugged. This is not the current case, but it doesn't hurt to be
future-safe here, specially since this code runs only once during
device probe. So, performance is not an issue here.
Reported-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Instead of copying exactly the same code on all USB devices,
add an ancillary routine that will create and fill the
struct media_device with the values imported from the USB
device.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Instead of copyping the same code on all PCI devices that
would have a media controller, add a core ancillary routine.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
The em28xx_v4l2_create_media_graph() is almost generic enough to
be at the core, as an ancillary function. Make it even more generic,
by getting rid of em28xx-specific code, relying only at the
media_device, in order to discover all entities found on PC-customer's
hardware and add it at the V4L2 core.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Shuah Khan