Return-path: Received: from nblzone-211-213.nblnetworks.fi ([83.145.211.213]:52962 "EHLO hillosipuli.retiisi.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727245AbeIZOVU (ORCPT ); Wed, 26 Sep 2018 10:21:20 -0400 From: Sakari Ailus To: linux-media@vger.kernel.org Cc: hverkuil@xs4all.nl Subject: [PATCH 2/2] v4l: ctrl: Provide unlocked variant of v4l2_ctrl_grab Date: Wed, 26 Sep 2018 11:09:37 +0300 Message-Id: <20180926080937.19501-3-sakari.ailus@linux.intel.com> In-Reply-To: <20180926080937.19501-1-sakari.ailus@linux.intel.com> References: <20180926080937.19501-1-sakari.ailus@linux.intel.com> Sender: linux-media-owner@vger.kernel.org List-ID: 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 --- drivers/media/v4l2-core/v4l2-ctrls.c | 8 ++++---- include/media/v4l2-ctrls.h | 26 +++++++++++++++++++++++++- 2 files changed, 29 insertions(+), 5 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c index ab393adf51eb..4c0ecf29d278 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls.c +++ b/drivers/media/v4l2-core/v4l2-ctrls.c @@ -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, 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 @@ -729,6 +729,22 @@ 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. * * @ctrl: The control to (de)activate. @@ -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() -- 2.11.0