svn commit: r335629 - in head: share/man/man4 sys/dev/vt/hw/vga

[Rodney W. Grimes]

> On Tue, Jun 26, 2018 at 05:21:27AM +0000, Alexey Dokuchaev wrote:
> > On Mon, Jun 25, 2018 at 08:43:51AM -0700, Rodney W. Grimes wrote:
> > > > New Revision: 335629
> > > > URL: https://svnweb.freebsd.org/changeset/base/335629
> > > > 
> > > > Log:
> > > >   vt: add option to ignore NO_VGA flag in ACPI
> > > >   
> > > >   To workaround buggy firmware that sets this flag when there's actually
> > > >   a VGA present.
> > > >   
> > > >   Reported and tested by:	Yasuhiro KIMURA <yasu at utahime.org>
> > > >   Sponsored by:		Citrix Systems R&D
> > > >   Reviewed by:		kib
> > > >   Differential revision:	https://reviews.freebsd.org/D16003
> > > 
> > > It is generally best to avoid double negatives,
> > > couldnt this of been better named? (hw.vga.acpi_force_vga)
> > 
> > Yes please; I get constantly confused when calculating negatives and
> > often get them wrong.
> 
> This is specifically done to workaround a firmware bug where some
> buggy firmwares set the NO_VGA flag in ACPI.

We are not conflicted about working around the buggy ACPI.

> So the option does
> exactly what the name says, it ignores the NO_VGA flag in ACPI. IMO
> acpi_force_vga is not as descriptive as the current name.

Interestingly that is the text you use to describe it in the man
page, so it seems as if it is good for the description, but not
good for the name of the flag itself?

.It Va hw.vga.acpi_ignore_no_vga
Set to 1 to force the usage of the VGA driver regardless of whether
ACPI IAPC_BOOT_ARCH signals no VGA support.
Can be used to workaround firmware bugs in the ACPI tables.

This does not mention the ACPI table entry being over ridden,
	 if (flags & ACPI_FADT_NO_VGA)

Further digging I believe you have placed this in the wrong
part of the hierarchy.  You put it in hw.vga, and it really
should be in hw.acpi.
Maybe hw.acpi.bootflags.ignore.no_vga.

Are there any other bootflags we may want to ignore?

Regards,
-- 
Rod Grimes                                                 rgrimes at freebsd.org