Date: Thu, 28 Jun 2018 06:16:26 -0700 (PDT) From: "Rodney W. Grimes" <freebsd@pdx.rh.CN85.dnsmgr.net> To: "Roger Pau Monn?" <royger@freebsd.org> Cc: Ian Lepore <ian@freebsd.org>, rgrimes@freebsd.org, Alexey Dokuchaev <danfe@freebsd.org>, svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r335629 - in head: share/man/man4 sys/dev/vt/hw/vga Message-ID: <201806281316.w5SDGQeH013219@pdx.rh.CN85.dnsmgr.net> In-Reply-To: <20180628093608.33yvnrwmmtj44get@mac.bytemobile.com>
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> On Tue, Jun 26, 2018 at 10:18:39AM -0600, Ian Lepore wrote: > > On Tue, 2018-06-26 at 08:55 -0700, Rodney W. Grimes wrote: > > > > > > > > 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@utahim > > > > > > > e.org> > > > > > > > ? Sponsored by: Citrix Systems R&D > > > > > > > ? Reviewed by: kib > > > > > > > ? Differential revision: https://reviews.freebsd.org/D > > > > > > > 16003 > > > > > > 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, > > > > > > There is ACPI_FADT_NO_CMOS_RTC, with an associated tunable > > hw.atrtc.enabled (default is -1), which can be: Shouldnt this really be in hw.acpi..... > > > > ? -1 - enabled unless acpi says ACPI_FADT_NO_CMOS_RTC > > ? ?0 - unconditionally disabled > > ? ?1 - unconditionally enabled > > > > The idea was that if RTC is provided by EFI runtime services, this flag > > would indicate that old-school CMOS RTC drivers should not be used. > > ?But, predictably, it turns out there are bioses that set this flag > > even when booting in legacy non-efi mode, leading to a need to ignore > > the flag and force use of the old driver. > > I could take this approach for vt and add hw.vt.enabled = { -1, 0, 1 } > if that seems better. Lets not scatter more ACPI stuff into non ACPI parts of the sysctl oid tree. If you do go this route it should really be in hw.acpi.* -- Rod Grimes rgrimes@freebsd.org
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