Created attachment 200276 [details]
Screenshot "See your local kernel hacker"
I got an AMD Radeon Pitcarain GPU. It runs smoothly on 11.2-RELEASE with dual monitor. As i upgraded to freebsd 12.0-RELEASE it shows just one monitor. As i read on the notes that there is amdgpu driver for newer cards HD7000+.
The radeonkms driver on 12.0 just activates one screen instead of both screens as on 11.2-RELEASE.
I took this screenshot (as i dont have a local kernel hacker)
I installed drm-kmod. Thats the reason why i choosed "ports & packages"
The following bug might be relatated to this one: bug #234044.
This is not a problem with the port itself but with the actual DRM. Please report this upstream (i.e., https://github.com/FreeBSDDesktop/kms-drm ) which is where these issues are being tracked and where they are being worked on and fixed. Thanks.
I opened a issue on github