One of the surest way to get your manager's back is to help them make their goals and put some stuff off their plates. Like other people said, most semi competent managers are aware of issues happening in their team. If you come up w/ some proposal to solve those issues, it will improve the team much more effectively than some feedback.

It also depends on your goals, but fixing some issues encountered by your manager is one of the most reliable way to promotion in up to mid size companies, unless your manager is a a*hole.