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From:   <Mario.Limonciello@dell.com>
To:     <robert.moore@intel.com>, <Alexander.Levin@microsoft.com>,
        <linux-kernel@vger.kernel.org>, <stable@vger.kernel.org>
CC:     <erik.schmauss@intel.com>, <rafael.j.wysocki@intel.com>
Subject: RE: [PATCH AUTOSEL for 4.4 093/167] ACPICA: Recognize the Windows 10
 version 1607 and 1703 OSI strings
Thread-Topic: [PATCH AUTOSEL for 4.4 093/167] ACPICA: Recognize the Windows 10
 version 1607 and 1703 OSI strings
Thread-Index: AQHTv5xaTVO5Yc6WFEyJ+eHwrZ3EpqPiKMtAgAPIEICAAAEjcA==
Date:   Wed, 28 Mar 2018 17:18:27 +0000
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References: <20180319160513.16384-1-alexander.levin@microsoft.com>
 <20180319160513.16384-93-alexander.levin@microsoft.com>
 <bc4e6f52fc2d45b5b7672c22aaa4dc55@ausx13mpc120.AMER.DELL.COM>
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> -----Original Message-----
> From: Moore, Robert [mailto:robert.moore@intel.com]
> Sent: Wednesday, March 28, 2018 12:16 PM
> To: Limonciello, Mario <Mario_Limonciello@Dell.com>;
> Alexander.Levin@microsoft.com; linux-kernel@vger.kernel.org;
> stable@vger.kernel.org
> Cc: Schmauss, Erik <erik.schmauss@intel.com>; Wysocki, Rafael J
> <rafael.j.wysocki@intel.com>
> Subject: RE: [PATCH AUTOSEL for 4.4 093/167] ACPICA: Recognize the Window=
s 10
> version 1607 and 1703 OSI strings
>=20
>=20
>=20
> > -----Original Message-----
> > From: Mario.Limonciello@dell.com [mailto:Mario.Limonciello@dell.com]
> > Sent: Monday, March 26, 2018 12:30 AM
> > To: Alexander.Levin@microsoft.com; linux-kernel@vger.kernel.org;
> > stable@vger.kernel.org
> > Cc: Moore, Robert <robert.moore@intel.com>; Schmauss, Erik
> > <erik.schmauss@intel.com>; Wysocki, Rafael J
> > <rafael.j.wysocki@intel.com>
> > Subject: RE: [PATCH AUTOSEL for 4.4 093/167] ACPICA: Recognize the
> > Windows 10 version 1607 and 1703 OSI strings
> >
> > > -----Original Message-----
> > > From: Sasha Levin [mailto:Alexander.Levin@microsoft.com]
> > > Sent: Monday, March 19, 2018 11:07 AM
> > > To: linux-kernel@vger.kernel.org; stable@vger.kernel.org
> > > Cc: Limonciello, Mario <Mario_Limonciello@Dell.com>; Bob Moore
> > > <robert.moore@intel.com>; Erik Schmauss <erik.schmauss@intel.com>;
> > Rafael J .
> > > Wysocki <rafael.j.wysocki@intel.com>; Sasha Levin
> > > <Alexander.Levin@microsoft.com>
> > > Subject: [PATCH AUTOSEL for 4.4 093/167] ACPICA: Recognize the Window=
s
> > > 10 version 1607 and 1703 OSI strings
> > >
> > > From: Mario Limonciello <mario.limonciello@dell.com>
> > >
> > > [ Upstream commit bc4d413a819f9d0764a80a55875a5d7e1f4efed4 ]
> > >
> > > ACPICA commit 35a4a3ea723b3066f575e63e5f0116f7ce65e713
> > >
> > > The public Microsoft document listing recognized OSI strings [1] show=
s
> > > that these two strings were introduced.
> > > version 1607 / Anniversary Update / "Redstone 1"
> > > version 1703 / Creators Update / "Redstone 2"
> > >
> > > [1]
> > > http://download.microsoft.com/download/7/e/7/7e7662cf-cbea-470b-a97e-
> > > ce7ce0d98dc2/winacpi_osi.docx
> > >
> > > Link: https://github.com/acpica/acpica/commit/35a4a3ea
> > > Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
> > > Signed-off-by: Bob Moore <robert.moore@intel.com>
> > > Signed-off-by: Erik Schmauss <erik.schmauss@intel.com>
> > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > > Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
> > > ---
> > >  drivers/acpi/acpica/utosi.c | 2 ++
> > >  include/acpi/actypes.h      | 2 ++
> > >  2 files changed, 4 insertions(+)
> > >
> > > diff --git a/drivers/acpi/acpica/utosi.c b/drivers/acpi/acpica/utosi.=
c
> > > index 8f3d203aed79..51d9011b5b33 100644
> > > --- a/drivers/acpi/acpica/utosi.c
> > > +++ b/drivers/acpi/acpica/utosi.c
> > > @@ -101,6 +101,8 @@ static struct acpi_interface_info
> > > acpi_default_supported_interfaces[] =3D {
> > >  	{"Windows 2012", NULL, 0, ACPI_OSI_WIN_8},	/* Windows 8 and Server
> > > 2012 - Added 08/2012 */
> > >  	{"Windows 2013", NULL, 0, ACPI_OSI_WIN_8},	/* Windows 8.1 and
> > Server
> > > 2012 R2 - Added 01/2014 */
> > >  	{"Windows 2015", NULL, 0, ACPI_OSI_WIN_10},	/* Windows 10 -
> > Added
> > > 03/2015 */
> > > +	{"Windows 2016", NULL, 0, ACPI_OSI_WIN_10_RS1},	/* Windows 10
> > > version 1607 - Added 12/2017 */
> > > +	{"Windows 2017", NULL, 0, ACPI_OSI_WIN_10_RS2},	/* Windows 10
> > > version 1703 - Added 12/2017 */
> > >
> > >  	/* Feature Group Strings */
> > >
> > > diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h index
> > > f914958c4adb..d27bc051f47f 100644
> > > --- a/include/acpi/actypes.h
> > > +++ b/include/acpi/actypes.h
> > > @@ -1284,6 +1284,8 @@ typedef enum {
> > >  #define ACPI_OSI_WIN_7                  0x0B
> > >  #define ACPI_OSI_WIN_8                  0x0C
> > >  #define ACPI_OSI_WIN_10                 0x0D
> > > +#define ACPI_OSI_WIN_10_RS1             0x0E
> > > +#define ACPI_OSI_WIN_10_RS2             0x0F
> > >
> > >  /* Definitions of file IO */
> > >
> > > --
> > > 2.14.1
> >
> > I don't believe that it would be a good idea to bring back this patch t=
o
> > kernels older than 4.15.  These strings do activate some extra features
> > in Windows and some BIOS ASL has been written to only activate them whe=
n
> > the newer Windows versions are detected. I have no concerns bringing
> > them to 4.15 though.
> >
> > Bringing them back to stable may introduce other problems that requires
> > backporting additional driver changes too.
>=20
> [Moore, Robert]
>=20
> There should be no problem with this change concerning older machines. Th=
e
> firmware on these machines will simply never call _OSI with any strings n=
ewer than
> when the firmware was written -- including this new one.
>=20
> Bob

Actually I'm referring to "newer" machines that do have this string in the =
firmware
but the changes in the kernel that are relevant to the string didn't land u=
ntil newer
kernels.

I think it's a pretty good risk for regressions on those older stable kerne=
ls as such.