[media] v4l2-core/v4l2-ctrls: Filter NOOP CH_RANGE events

If modify_range is called but no range is changed, do not send the
CH_RANGE event.

Reported-by: Dimitrios Katsaros <patcherwork@gmail.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 4a1d9fd..f9c0e81 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -3300,7 +3300,8 @@ EXPORT_SYMBOL(v4l2_ctrl_notify);
 int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
                        s64 min, s64 max, u64 step, s64 def)
 {
-       bool changed;
+       bool value_changed;
+       bool range_changed = false;
        int ret;
 
        lockdep_assert_held(ctrl->handler->lock);
@@ -3324,10 +3325,14 @@ int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
        default:
                return -EINVAL;
        }
-       ctrl->minimum = min;
-       ctrl->maximum = max;
-       ctrl->step = step;
-       ctrl->default_value = def;
+       if ((ctrl->minimum != min) || (ctrl->maximum != max) ||
+               (ctrl->step != step) || ctrl->default_value != def) {
+               range_changed = true;
+               ctrl->minimum = min;
+               ctrl->maximum = max;
+               ctrl->step = step;
+               ctrl->default_value = def;
+       }
        cur_to_new(ctrl);
        if (validate_new(ctrl, ctrl->p_new)) {
                if (ctrl->type == V4L2_CTRL_TYPE_INTEGER64)
@@ -3337,12 +3342,12 @@ int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
        }
 
        if (ctrl->type == V4L2_CTRL_TYPE_INTEGER64)
-               changed = *ctrl->p_new.p_s64 != *ctrl->p_cur.p_s64;
+               value_changed = *ctrl->p_new.p_s64 != *ctrl->p_cur.p_s64;
        else
-               changed = *ctrl->p_new.p_s32 != *ctrl->p_cur.p_s32;
-       if (changed)
+               value_changed = *ctrl->p_new.p_s32 != *ctrl->p_cur.p_s32;
+       if (value_changed)
                ret = set_ctrl(NULL, ctrl, V4L2_EVENT_CTRL_CH_RANGE);
-       else
+       else if (range_changed)
                send_event(NULL, ctrl, V4L2_EVENT_CTRL_CH_RANGE);
        return ret;
 }