Are you trying to use it as an access point or something else?
Without TD-W8980, how did you access internet?

Hi, I currently have a dedicated ADSL modem (TD-8817), which is in bridged mode to a Linux server, which performs a lot of tasks. I then have a dedicated wireless access point, but all the DHCP, NAT, etc is performed on the Linux server. (ie. The AP is just a dumb wireless-to-ethernet bridge)

I was wondering about upgrading the access point to a newer, faster one - and was wondering if I can reduce the stack of boxes from two to one. But I still need the ADSL bridged to my linux server.

Not quite sure if it will be working...You want to use a wireless modem router to replace the bridage modem and access point, right?
The modem router can be configured as an access point with DHCP off.

I know I can configure the ADSL modem/router as JUST an access point. Or as JUST a bridged modem... but can I get it to do both those things at once?
ie. Be an ADSL bridge to my server *and* be a wireless access point?

thanks for your patience.

There is no conflict between ADSL line and access point but the problem is that I cannot tell if your internet will be working as before.