OK thanks. Let's assume that I DO have frequent interference from radar; I assume that I can turn off the DFS feature on the AP so it does not waste time/resources trying the DFS channels?
Indeed, you are not compelled to be using the DFS channels at all; actually given that the HD type of AP sports a way stronger 5GHz signal as compared to its non-high density counterpart you may not need to rely on DFS channels at all;
Exactly! DFS channels are optional on the AP, so you can decide whether to use or not with these channels depending on your environment.
Thanks @RTH10 for the answer.