Comment # 11 on bug 1105974 from Andres Nogueiras

(In reply to Takashi Iwai from comment #10)
> There is little we can help about nouveau from our side for this kind of
> bug, unfortunately.
> 
> Could you try the latest upstream kernel in OBS Kernel:stable repo, and see
> whether the problem persists?  Just download the kernel-default.rpm from the
> repository and install on top of your Leap 15.1 system.
> 
> If the problem persists with the upstream kernel, it's better to report to
> upstream.  OTOH, if the latest upstream works, we still have some chance for
> backporting a fix.

I've installed and try the kernel-default-5.4.1-2.1.gfcf6204.x86_64

It just works (boots, let me connect to net, X11 works, not too much more
tested), but throws even more messages on dmesg, and many of them are pretty
similar to the previous ones.

Adding the dmesg dump (boot and poweroff) for this.