Is there an AMD driver for FirePro M6100 in a Dell Precision M6800 that will work with Linux Mint v19? The open source kernel driver that installs by default does not support Vulcan.
The last Mobile Firepro Graphic drivers for Linux for you particular DELL at AMD is from 2015: AMD FirePro™ Mobility Driver .
Try posting your question here : https://www.phoronix.com/forums/forum/linux-graphics-x-org-drivers/amd-linux unless this is where you got your open source Linux driver from.