Popover from middle of the item in ng-repeat

My app just upgraded with v1-0-0-beta-12 which supports popping from bottom or top of screen. Now I found problem in popping it from middle of the item when popover height is fixed.
I am opening popover from my list like

        <div ng-repeat="item in myItems" >
                   <ion-option-button  ng-click="openPopover($event)"> Action</ion-option-button>

and I am setting fix height to popover view like

<style>.popover { height:470px; }</style>

now when I open popover from middle of the item, it truncates the top content of the popover view when It has no space in top or bottom screen for the defined height (470px). I think it must come with scrolling with available height on top or bottom. Any one have any idea to resolve this issue.
Please help.