Always make sure to do your work and to communicate effectively that you're doing your work, facing hard problems and working hard. Communicating this effectively is far more important than actually doing it, so I'd recommend spending 90% of your working time on this communication, and no more than 10% of your working time on actual problem solving. You are a salaried employee. The only thing you really need to care about is how your manager and their manager feels about you.