Comment # 6 on bug 1188954 from Felix Miata

(In reply to Stefan Dirsch from comment #5)
> So things are simply working with default "radeon" kernel driver. No idea
> what's remaining here.

The amdgpu DDX driver behaved totally as expected on TW until relatively
recently. I have no recollection when it stopped behaving normally, but I'm
guessing I was hoping when it first occurred it was temporary or fluke and
would disappear on its own. I cannot reproduce on the same PC using Debian 10
or 11, Fedora 34 or Leap 15.3. They all work perfectly fine at the outset with
amdgpu kernel driver, radeon.cik_support=0 amdgpu.cik_support=1 and the amdgpu
DDX. TW works fine too, except on initial X start at boot.

There is one other openSUSE quirk, and that is that 15.3 will not load the
amdgpu DDX unless explicitly directed in /etc/X11/xorg.conf.d/ via Driver
"amdgpu". All others need no help from /etc/X11/xorg.con*.

There is a Fedora quirk too, which I doubt is connected, because it also
happens with kernel-radeon/X-modesetting. When X starts SDDM, X immediately
crashes and restarts, with this Xorg.0.log.old tail:
[    12.301] (II) UnloadModule: "libinput"
[    12.303] (WW) xf86OpenConsole: VT_ACTIVATE failed: Input/output error
[    12.303] (EE)
Fatal server error:
[    12.303] (EE) xf86OpenConsole: Switching VT failed
...
[    12.303] (WW) xf86CloseConsole: KDSETMODE failed: Input/output error
[    12.303] (WW) xf86CloseConsole: VT_GETMODE failed: Input/output error
[    12.303] (WW) xf86CloseConsole: VT_ACTIVATE failed: Input/output error
[    12.303] (EE) Server terminated with error (1). Closing log file.

Maybe it just needs more time to go away magically, or show up somewhere else.
:P

I have lots of freespace on the SSD, so when I get the urge or need to do a
fresh install of TW I'll see if it reproduces.