P11D and overdrawn DLA

I've trawled through previous threads and found conflicting views on both of my queries:

1. Is a P11D entry required when the director has been charged interest on his overdrawn DLA at official HMRC rates so that there is no benefit?

2. Is it OK to add the interest to the DLA or does he have to be shown to pay it with a transfer of funds?

Thanks for any help with this.