path: root/include/media/v4l2-ctrls.h
diff options
authorSakari Ailus <sakari.ailus@iki.fi>2012-01-24 21:05:34 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2012-05-14 08:46:27 -0300
commit77e7c4e624404c6edb5686b3d5f873c6008ed6b0 (patch)
tree1ba1d9903bb8eca6e3ca3439d3a5981274ea86ba /include/media/v4l2-ctrls.h
parent8227c92b69688403dee2adf5f399a49539ae5049 (diff)
[media] v4l: Allow changing control handler lock
Allow choosing the lock used by the control handler. This may be handy sometimes when a driver providing multiple subdevs does not want to use several locks to serialise its functions. Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'include/media/v4l2-ctrls.h')
1 files changed, 6 insertions, 3 deletions
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index c6f6b4c2c5f2..dde6fbacc271 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -167,7 +167,9 @@ struct v4l2_ctrl_ref {
/** struct v4l2_ctrl_handler - The control handler keeps track of all the
* controls: both the controls owned by the handler and those inherited
* from other handlers.
+ * @_lock: Default for "lock".
* @lock: Lock to control access to this handler and its controls.
+ * May be replaced by the user right after init.
* @ctrls: The list of controls owned by this handler.
* @ctrl_refs: The list of control references.
* @cached: The last found control reference. It is common that the same
@@ -178,7 +180,8 @@ struct v4l2_ctrl_ref {
* @error: The error code of the first failed control addition.
struct v4l2_ctrl_handler {
- struct mutex lock;
+ struct mutex _lock;
+ struct mutex *lock;
struct list_head ctrls;
struct list_head ctrl_refs;
struct v4l2_ctrl_ref *cached;
@@ -455,7 +458,7 @@ void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
- mutex_lock(&ctrl->handler->lock);
+ mutex_lock(ctrl->handler->lock);
/** v4l2_ctrl_lock() - Helper function to unlock the handler
@@ -464,7 +467,7 @@ static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
- mutex_unlock(&ctrl->handler->lock);
+ mutex_unlock(ctrl->handler->lock);
/** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver.

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