Comment # 25 on bug 1193640 from Felix Miata

(In reply to Takashi Iwai from comment #21)
> We have already kABI freeze, and only P1 bugs are accepted for the GM kernel.
> The rest fixes (including this) are merged to the maintenance update kernel
> that will be released right after GM release.

It ought to be P1. People are going to migrate elsewhere when they try to
install and get a lockup instead of a 15.4 installation started on their year+
old computers come May or June. It's not just my Asus B560M-A that's affected,
but also Asus TUF GAMING Z590-PLUS WIFI[1], ASRock B560 Steel Legend and ASRock
H570M-ITX/ac that we know of. Others reported this without including
motherboard or PC model numbers. It looks like the whole B5xx series of
products from Asus & ASRock are likely affected, and it could be half the
FCLGA1200 series potentially. That'll be really lovely for openSUSE reputation
if Fedora 36 and Ubuntu 22.04 get released in April with this fix in it but
Leap a month or two later does not.

This isn't just affecting use of the motherboard's own video ports. It also
happens when a discrete GPU card is installed and attempt is made to use 2
displays. Which card I tested with I don't remember, but I doubt it matters.
And for this reason, I'm betting the following thread was caused by this bug:
<https://lists.opensuse.org/archives/list/support@lists.opensuse.org/thread/D4MKVTQANHNSHMXGE5CYN53LKUTZTLQ7/>
That user returned his Dell to the vendor because of his problem. Luckily he
was a long time openSUSE user, so wasn't chased away by this.

> > Is 15.3 going to get
> > this fix backported?

> Unlikely.  The patches are not compatible with the older DRM code at all,
> hence not trivial to backport.  

Which kernel repo should people enable to participate in 15.4 Alpha & Beta
development? After all, I did report this specifically as a Leap (installation)
bug, not TW. ;)

> > It seems simpledrm is in it too. Is this correct?

> It's not enabled as default.  You still need to specify a special boot
> option to boot with simpledrm (and the option is temporary, only for
> (open)SUSE downstream).

What option would that be? Not one in
https://www.kernel.org/doc/Documentation/admin-guide/kernel-parameters.txt I
suppose. ;)

[1] I spent quite a bit of time over more than a week trying to help someone
with a TUF GAMING Z590-PLUS WIFI here:
https://www.linuxquestions.org/questions/linux-desktop-74/dual-monitors-setup-and-drivers-4175701245/