OK. Sorry about that, lloydsmart...
(I'll look for that kind of sites, that let one paste big ammounts of text,
the next time I have to paste this kind of stuff.)
Relating to the problem reported...
I've just noticed that, if (like I've seen people saying, in here, for one to
do) I include in the file "/etc/X11/xorg.conf.d/20-nouveau.conf", that
nouveau tells me to create:
Section "Device"
Identifier "*nvidia*"
Driver "nouveau"
EndSection
instead of the recommended:
Section "Device"
Identifier "*n*"
Driver "nouveau"
EndSection
This problem, of the error reported in the thread title ("nouveau '[mi] EQ
overflowing'"), disappears.
Yet, I still get a black screen (or something of the sort, depending on other
variables). And, I'm not able to log in.
I'll make more tests (and, paste more stuff, if I think it's worth it)
tomorrow.
Thank you very much, for your help, Michał Masłowski.
I will make tests with other kernels too.