From 7a9b109d91cfc6089006378efd515cc287bdef67 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Thu, 19 Jul 2018 07:11:40 -0400 Subject: 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 Acked-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- include/media/v4l2-ctrls.h | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) (limited to 'include/media') diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h index f615ba1b29dd..ff89df428f79 100644 --- a/include/media/v4l2-ctrls.h +++ b/include/media/v4l2-ctrls.h @@ -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() -- cgit v1.2.3