Possible bug in acpi_video(4)

[MrPhyber]

> > Hello everyone,
> > my laptop is an Acer Swift SF315-41 with an AMD Ryzen 2500U.
> > I'm on FreeBSD 12.1-RELEASE-p5 with drm-fbsd12-kmod (amdgpu).
> > Everything works on this machine except for the hardware brightness controls.
> > On OpenBSD and Linux they work like a charm, and so I think that there is a
> > problem in acpi_video(4). I will attach dmesg and acpidump. Whenever I
> > try to use the hardware brightness switches, this pops up on
> > the system messages: "can't evaluate \SB.PCI0.GP17.VGA_.LCD_._BQC - AE_NOT_FOUND". As you will see, FreeBSD sees acpi_video0 only, and this is
> > always inactive (sysctl: hw.acpi.video.lcd0.active = 0), but OpenBSD sees acpi_video0, acpi_video1, and others with VGA. Don't know what's the
> > matter here, any suggestions?
>
> Please see
> https://svnweb.freebsd.org/base?view=revision&revision=360657
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=207086
>
> ------------------------------------------------------------------------------------------------------------------------------------
>
> Andriy Gapon

I tried the patch you sent, and I have a few questions:
1) when will this patch be avaiable on 12.1-RELEASE?
2) now the system does not spit out any more errors like
the one complaining about _BQC missing: in fact it doesn't
give errors at all, but the hardware brightness controls still
won't work. Now hw.acpi.video.lcd0.active = 1 but if I try
to modify hw.acpi.video.lcd0.brightness nothing appens. I
still think that acpi_video doesn't see all video outputs
(I investigated a bit further and on OpenBSD there are
acpivouts on dmesg output, could be an hint). What could
be wrong?