call wp_update_post() from save_post action

Hello, I am trying to update a post entry after it has been saved. I am trying:

add_action("save_post", 'my_func');

function my_func($id)
{
	if(wp_is_post_revision($id) || wp_is_post_autosave($id)) return;

	wp_update_post( array('ID'=>$id, ... ) );
}

but this causes an infinite recursion loop. Is this possible with the action hooks architecture? Or do I need to use a query? Thanks.