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media: v4l: ctrl: Provide unlocked variant of v4l2_ctrl_grab 

Sometimes it may be necessary to grab a control while holding the control
handler's lock. Provide an unlocked variant of v4l2_ctrl_grab for the
purpose --- it's called __v4l2_ctrl_grab.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Sakari Ailus 2018-07-19 07:11:40 -04:00 committed by Mauro Carvalho Chehab
parent 9a8aaa28f5
commit 7a9b109d91
2 changed files with 29 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/media/v4l2-core/v4l2-ctrls.c
View File

@ -2511,14 +2511,15 @@ void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active)
}
EXPORT_SYMBOL(v4l2_ctrl_activate);
void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
void __v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
{
bool old;
if (ctrl == NULL)
return;
v4l2_ctrl_lock(ctrl);
lockdep_assert_held(ctrl->handler->lock);
if (grabbed)
/* set V4L2_CTRL_FLAG_GRABBED */
old = test_and_set_bit(1, &ctrl->flags);
@ -2527,9 +2528,8 @@ void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
old = test_and_clear_bit(1, &ctrl->flags);
if (old != grabbed)
send_event(NULL, ctrl, V4L2_EVENT_CTRL_CH_FLAGS);
v4l2_ctrl_unlock(ctrl);
}
EXPORT_SYMBOL(v4l2_ctrl_grab);
EXPORT_SYMBOL(__v4l2_ctrl_grab);
/* Log the control name and value */
static void log_ctrl(const struct v4l2_ctrl *ctrl,

26
include/media/v4l2-ctrls.h
View File

@ -728,6 +728,22 @@ struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
*/
void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
/**
* __v4l2_ctrl_grab() - Unlocked variant of v4l2_ctrl_grab.
*
* @ctrl: The control to (de)activate.
* @grabbed: True if the control should become grabbed.
*
* This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
* Does nothing if @ctrl == NULL.
* The V4L2_EVENT_CTRL event will be generated afterwards.
* This will usually be called when starting or stopping streaming in the
* driver.
*
* This function assumes that the control handler is locked by the caller.
*/
void __v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
/**
* v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
*
@ -743,7 +759,15 @@ void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
* This function assumes that the control handler is not locked and will
* take the lock itself.
*/
void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
static inline void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
{
if (!ctrl)
return;
v4l2_ctrl_lock(ctrl);
__v4l2_ctrl_grab(ctrl, grabbed);
v4l2_ctrl_unlock(ctrl);
}
/**
*__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()