I must also remind you that the kms cannot be turned off since 3.9(?) kernels and that was a quick solution on Debian 7,8. In case the installer team wishes to add f/w request code, the pci device id is 673e. I am almost certain that many other amd gpus will have the same problem and I will check some of my own cards later this week.
Hello to the Debian installer developers, once again, this 4head card is
unusable in Debian. It would not work at all on Debian 7 (bug #747218)
while it worked on Debian 8. Now it fails to work on Stretch.
This time Xorg cannot start at all UNLESS firmware-amd-graphics is
installed from command line.I did not file a bug report since I do not
want to run reportbug from cli. If the card is unusable on Debian 9
without the firmware why didn't the installer ask for it?