| Message ID | 20180926080937.19501-3-sakari.ailus@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Unlocked v4l2_ctrl_grab | expand |
On 09/26/2018 10:09 AM, Sakari Ailus wrote: > 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> Regards, Hans > --- > 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() >
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()
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> --- drivers/media/v4l2-core/v4l2-ctrls.c | 8 ++++---- include/media/v4l2-ctrls.h | 26 +++++++++++++++++++++++++- 2 files changed, 29 insertions(+), 5 deletions(-)