What a joke! Why would they even consider removing an option that many people rely on to have their displays working correctly. I wait with baited breathe for a new release of their linux drivers which generally have terrible performance and support and make my life more difficult every day. Then when they do start paying attention to the driver I hope for even a tiny improvement in performance, but no they remove a crucial setting that means I cannot even use my display properly. Well done AMD. Thank you my choice of brand for my next graphics card easier.
Here is a fix to the problem.
This did not work right away for me I had to go through the entire /etc/ati/amdpcsdb file and edit every entry with xxxxUnderscanxxx=V1 changing to V0.
log out and log back in and it's fixed.
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