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path: root/include/media/v4l2-fh.h
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2018-10-03media: v4l: event: Prevent freeing event subscriptions while accessedSakari Ailus1-0/+4
The event subscriptions are added to the subscribed event list while holding a spinlock, but that lock is subsequently released while still accessing the subscription object. This makes it possible to unsubscribe the event --- and freeing the subscription object's memory --- while the subscription object is simultaneously accessed. Prevent this by adding a mutex to serialise the event subscription and unsubscription. This also gives a guarantee to the callback ops that the add op has returned before the del op is called. This change also results in making the elems field less special: subscriptions are only added to the event list once they are fully initialised. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: stable@vger.kernel.org # for 4.14 and up Fixes: c3b5b0241f62 ("V4L/DVB: V4L: Events: Add backend") Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-02-26media: v4l2_fh.h: add missing kconfig.h includeAlexandre Courbot1-0/+1
v4l2_fh.h uses the IS_ENABLED() macro and thus should include kconfig.h. Signed-off-by: Alexandre Courbot <acourbot@chromium.org> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-01-27[media] media: Drop FSF's postal address from the source code filesSakari Ailus1-5/+0
Drop the FSF's postal address from the source code files that typically contain mostly the license text. Of the 628 removed instances, 578 are outdated. The patch has been created with the following command without manual edits: git grep -l "675 Mass Ave\|59 Temple Place\|51 Franklin St" -- \ drivers/media/ include/media|while read i; do i=$i perl -e ' open(F,"< $ENV{i}"); $a=join("", <F>); $a =~ s/[ \t]*\*\n.*You should.*\n.*along with.*\n.*(\n.*USA.*$)?\n//m && $a =~ s/(^.*)Or, (point your browser to) /$1To obtain the license, $2\n$1/m; close(F); open(F, "> $ENV{i}"); print F $a; close(F);'; done Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
2016-07-23[media] v4l2-fh.h: add documentation for itMauro Carvalho Chehab1-32/+96
This header file was undocumented. Add documentation for it. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2013-12-04[media] V4L: Add mem2mem ioctl and file operation helpersSylwester Nawrocki1-0/+4
This patch adds ioctl helpers to the V4L2 mem-to-mem API, so we can avoid several ioctl handlers in the mem-to-mem video node drivers that are simply a pass-through to the v4l2_m2m_* calls. These helpers will only be useful for drivers that use same mutex for both OUTPUT and CAPTURE queue, which is the case for all currently in tree v4l2 m2m drivers. In order to use the helpers the drivers are required to use struct v4l2_fh. Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-10-17[media] v4l2-fh: Include linux/videodev2.h for enum v4l2_priority definitionLaurent Pinchart1-0/+1
struct v4l2_fh has an enum v4l2_priority field. Make sure the enum definition is available by including linux/videodev2.h. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-10-17[media] v4l2-fh: Include linux/fs.h for struct file definitionLaurent Pinchart1-0/+1
v4l2-fh.h dereferences struct file, the structure must thus be defined. Pull in its definition by including linux/fs.h. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2012-11-21[media] v4l, smiapp, smiapp-pll, adp1653: Update contact informationSakari Ailus1-1/+1
Update contact information to correspond my e-mail address changes. Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-07-27[media] v4l2-event/ctrls/fh: allocate events per fh and per type instead of ↵Hans Verkuil1-2/+0
just per-fh The driver had to decide how many events to allocate when the v4l2_fh struct was created. It was possible to add more events afterwards, but there was no way to ensure that you wouldn't miss important events if the event queue would fill up for that filehandle. In addition, once there were no more free events, any new events were simply dropped on the floor. For the control event in particular this made life very difficult since control status/value changes could just be missed if the number of allocated events and the speed at which the application read events was too low to keep up with the number of generated events. The application would have no idea what the latest state was for a control since it could have missed the latest control change. So this patch makes some major changes in how events are allocated. Instead of allocating events per-filehandle they are now allocated when subscribing an event. So for that particular event type N events (determined by the driver) are allocated. Those events are reserved for that particular event type. This ensures that you will not miss events for a particular type altogether. In addition, if there are N events in use and a new event is raised, then the oldest event is dropped and the new one is added. So the latest event is always available. This can be further improved by adding the ability to merge the state of two events together, ensuring that no data is lost at all. This will be added in the next patch. This also makes it possible to allow the user to determine the number of events that will be allocated. This is not implemented at the moment, but would be trivial. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-07-27[media] v4l2-events/fh: merge v4l2_events into v4l2_fhHans Verkuil1-3/+10
Drivers that supported events used to be rare, but now that controls can also raise events this will become much more common since almost all drivers have controls. This means that keeping struct v4l2_events as a separate struct make no more sense. Merging it into struct v4l2_fh simplifies things substantially as it is now an integral part of the filehandle struct. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-07-27[media] v4l2-ioctl: add ctrl_handler to v4l2_fhHans Verkuil1-0/+2
This is required to implement control events and is also needed to allow for per-filehandle control handlers. Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-03-22[media] v4l2-fh: add v4l2_fh_is_singularHans Verkuil1-0/+13
Several drivers need to do something when the first filehandle is opened or the last filehandle is closed. Most implement some use count mechanism, but if they use v4l2_fh, then you can also just check if this is the only filehandle for the device node. A simple helper function can do this. Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-03-22[media] v4l2-fh: add v4l2_fh_open and v4l2_fh_release helper functionsHans Verkuil1-0/+15
Add two new functions: v4l2_fh_open allocates and initializes a struct v4l2_fh based on a struct file pointer and v4l2_fh_release releases and frees a struct v4l2_fh. Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-03-22[media] v4l2-fh: implement v4l2_priority supportHans Verkuil1-0/+1
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2010-05-19V4L/DVB: V4L: Events: Add backendSakari Ailus1-0/+2
Add event handling backend to V4L2. The backend handles event subscription and delivery to file handles. Event subscriptions are based on file handle. Events may be delivered to all subscribed file handles on a device independent of where they originate from. Signed-off-by: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2010-05-19V4L/DVB: V4L: File handlesSakari Ailus1-0/+63
This patch adds a list of v4l2_fh structures to every video_device. It allows using file handle related information in V4L2. The event interface is one example of such use. The use of v4l2_fh is not mandatory for drivers. Signed-off-by: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>