From 9ea1b7a4b66fddfab9e65e243b72d18371f8d9a5 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Fri, 17 Jan 2014 08:25:26 -0300 Subject: [PATCH] [media] v4l2-ctrls: compare values only once When setting a control the control's new value is compared to the current value twice: once by new_to_cur(), once by cluster_changed(). Not a big deal when dealing with simple values, but it can be a problem when dealing with compound types or arrays. So fix this: cluster_changed() sets the has_changed flag, which is used by new_to_cur() instead of having to do another compare. Signed-off-by: Hans Verkuil Reviewed-by: Sylwester Nawrocki Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/v4l2-ctrls.c | 17 +++++++++++------ include/media/v4l2-ctrls.h | 3 +++ 2 files changed, 14 insertions(+), 6 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c index e7e0beab7048..1b4d37ce4afe 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls.c +++ b/drivers/media/v4l2-core/v4l2-ctrls.c @@ -1424,8 +1424,11 @@ static void new_to_cur(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, u32 ch_flags) if (ctrl == NULL) return; - changed = !ctrl->type_ops->equal(ctrl, ctrl->p_cur, ctrl->p_new); - ptr_to_ptr(ctrl, ctrl->p_new, ctrl->p_cur); + + /* has_changed is set by cluster_changed */ + changed = ctrl->has_changed; + if (changed) + ptr_to_ptr(ctrl, ctrl->p_new, ctrl->p_cur); if (ch_flags & V4L2_EVENT_CTRL_CH_FLAGS) { /* Note: CH_FLAGS is only set for auto clusters. */ @@ -1462,17 +1465,19 @@ static void cur_to_new(struct v4l2_ctrl *ctrl) value that differs from the current value. */ static int cluster_changed(struct v4l2_ctrl *master) { - int diff = 0; + bool changed = false; int i; - for (i = 0; !diff && i < master->ncontrols; i++) { + for (i = 0; i < master->ncontrols; i++) { struct v4l2_ctrl *ctrl = master->cluster[i]; if (ctrl == NULL) continue; - diff = !ctrl->type_ops->equal(ctrl, ctrl->p_cur, ctrl->p_new); + ctrl->has_changed = !ctrl->type_ops->equal(ctrl, + ctrl->p_cur, ctrl->p_new); + changed |= ctrl->has_changed; } - return diff; + return changed; } /* Control range checking */ diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h index ddd9fdf1ac1a..a38bd55909b2 100644 --- a/include/media/v4l2-ctrls.h +++ b/include/media/v4l2-ctrls.h @@ -96,6 +96,8 @@ typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv); * @is_new: Set when the user specified a new value for this control. It * is also set when called from v4l2_ctrl_handler_setup. Drivers * should never set this flag. + * @has_changed: Set when the current value differs from the new value. Drivers + * should never use this flag. * @is_private: If set, then this control is private to its handler and it * will not be added to any other handlers. Drivers can set * this flag. @@ -158,6 +160,7 @@ struct v4l2_ctrl { unsigned int done:1; unsigned int is_new:1; + unsigned int has_changed:1; unsigned int is_private:1; unsigned int is_auto:1; unsigned int is_int:1; -- 2.20.1