Blacklisted radeon module on kernel to force amdgpu, get black screen

I have a radeon r7 260x and i’m trying to force my system to use amdgpu drivers. In the grub default line i added modprobe.blacklist=radeon to block radeon, also enabled cik compat for amdgpu, tried with 5.4 and 5.7 kernels, none work, any idea?

Graphics:
Device-1: AMD Bonaire XTX [Radeon R7 260X/360] vendor: PC Partner Limited
driver: radeon v: kernel alternate: amdgpu bus ID: 01:00.0
chip ID: 1002 6658
Display: x11 server: XOrg 1.20.8 compositor: kwin_x11 driver: radeon
FAILED: ati unloaded: modesetting alternate: fbdev,vesa display ID: :0
screens: 1
Screen-1: 0 s-res: 2726x768 s-dpi: 96 s-size: 721x203mm (28.4x8.0")
s-diag: 749mm (29.5")
Monitor-1: HDMI-0 res: 1366x768 hz: 60 dpi: 85 size: 410x230mm (16.1x9.1")
diag: 470mm (18.5")
Monitor-2: DVI-1 res: 1360x768 hz: 60 dpi: 85 size: 406x229mm (16.0x9.0")
diag: 466mm (18.4")
OpenGL: renderer: AMD BONAIRE (DRM 2.50.0 5.7.19-2-MANJARO LLVM 10.0.1)
v: 4.5 Mesa 20.1.7 direct render: Yes

Dmesg:

https://pastebin.pl/view/3368fbba

volcanic islands should be supported … but I think there was another similar thread about amdgpu not starting with it …
maybe also check for anything setting radeon in /etc/X11/{mhwd,xorg.conf}.d/ ?

Your pastebin link is dead, FYI.
EDIT: Fixed it.

You could try the amdgpu-experimental repo package, it should set everything properly. If you can’t boot after installing it, just switch to a TTY, uninstall it and reboot.

https://pastebin.pl/view/3368fbba

Experimental worked, but now I have a new problem, my second monitor wont work. If it matters, its being recognized… In KDE settings I can see it, windows are on it, and I can disable it to bring everything to one monitor… There is just no image at all, it goes into power saving mode immediately after grub, never showing anything

https://pastebin.pl/view/d69903ca

thats the new dmesg, with one screen working and the other just in eco mode, if there is anything else I can provide, please tell me so