From owner-svn-src-all@freebsd.org Tue Jun 26 16:18:48 2018 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A779410010D0 for ; Tue, 26 Jun 2018 16:18:48 +0000 (UTC) (envelope-from ian@freebsd.org) Received: from pmta2.delivery6.ore.mailhop.org (pmta2.delivery6.ore.mailhop.org [54.200.129.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 2BBE877499 for ; Tue, 26 Jun 2018 16:18:48 +0000 (UTC) (envelope-from ian@freebsd.org) X-MHO-RoutePath: aGlwcGll X-MHO-User: 9658fb4f-795c-11e8-b829-b3adae557cda X-Report-Abuse-To: https://support.duocircle.com/support/solutions/articles/5000540958-duocircle-standard-smtp-abuse-information X-Originating-IP: 67.177.211.60 X-Mail-Handler: DuoCircle Outbound SMTP Received: from ilsoft.org (unknown [67.177.211.60]) by outbound2.ore.mailhop.org (Halon) with ESMTPSA id 9658fb4f-795c-11e8-b829-b3adae557cda; Tue, 26 Jun 2018 16:18:40 +0000 (UTC) Received: from rev (rev [172.22.42.240]) by ilsoft.org (8.15.2/8.15.2) with ESMTP id w5QGIdX9099056; Tue, 26 Jun 2018 10:18:39 -0600 (MDT) (envelope-from ian@freebsd.org) Message-ID: <1530029919.24573.74.camel@freebsd.org> Subject: Re: svn commit: r335629 - in head: share/man/man4 sys/dev/vt/hw/vga From: Ian Lepore To: rgrimes@freebsd.org, Roger Pau Monn? Cc: Alexey Dokuchaev , svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Date: Tue, 26 Jun 2018 10:18:39 -0600 In-Reply-To: <201806261555.w5QFtURn003981@pdx.rh.CN85.dnsmgr.net> References: <201806261555.w5QFtURn003981@pdx.rh.CN85.dnsmgr.net> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.18.5.1 FreeBSD GNOME Team Port Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 26 Jun 2018 16:18:48 -0000 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 > > > > 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:   -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. -- Ian