RE: [PATCH AUTOSEL for 4.4 093/167] ACPICA: Recognize the Windows 10 version 1607 and 1703 OSI strings

[Mario.Limonciello]

> -----Original Message-----
> From: Moore, Robert [mailto:robert.moore@xxxxxxxxx]
> Sent: Wednesday, March 28, 2018 12:16 PM
> To: Limonciello, Mario <Mario_Limonciello@xxxxxxxx>;
> Alexander.Levin@xxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> stable@xxxxxxxxxxxxxxx
> Cc: Schmauss, Erik <erik.schmauss@xxxxxxxxx>; Wysocki, Rafael J
> <rafael.j.wysocki@xxxxxxxxx>
> Subject: RE: [PATCH AUTOSEL for 4.4 093/167] ACPICA: Recognize the Windows 10
> version 1607 and 1703 OSI strings
> 
> 
> 
> > -----Original Message-----
> > From: Mario.Limonciello@xxxxxxxx [mailto:Mario.Limonciello@xxxxxxxx]
> > Sent: Monday, March 26, 2018 12:30 AM
> > To: Alexander.Levin@xxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> > stable@xxxxxxxxxxxxxxx
> > Cc: Moore, Robert <robert.moore@xxxxxxxxx>; Schmauss, Erik
> > <erik.schmauss@xxxxxxxxx>; Wysocki, Rafael J
> > <rafael.j.wysocki@xxxxxxxxx>
> > 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@xxxxxxxxxxxxx]
> > > Sent: Monday, March 19, 2018 11:07 AM
> > > To: linux-kernel@xxxxxxxxxxxxxxx; stable@xxxxxxxxxxxxxxx
> > > Cc: Limonciello, Mario <Mario_Limonciello@xxxxxxxx>; Bob Moore
> > > <robert.moore@xxxxxxxxx>; Erik Schmauss <erik.schmauss@xxxxxxxxx>;
> > Rafael J .
> > > Wysocki <rafael.j.wysocki@xxxxxxxxx>; Sasha Levin
> > > <Alexander.Levin@xxxxxxxxxxxxx>
> > > Subject: [PATCH AUTOSEL for 4.4 093/167] ACPICA: Recognize the Windows
> > > 10 version 1607 and 1703 OSI strings
> > >
> > > From: Mario Limonciello <mario.limonciello@xxxxxxxx>
> > >
> > > [ Upstream commit bc4d413a819f9d0764a80a55875a5d7e1f4efed4 ]
> > >
> > > ACPICA commit 35a4a3ea723b3066f575e63e5f0116f7ce65e713
> > >
> > > The public Microsoft document listing recognized OSI strings [1] shows
> > > 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@xxxxxxxx>
> > > Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx>
> > > Signed-off-by: Erik Schmauss <erik.schmauss@xxxxxxxxx>
> > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> > > Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
> > > ---
> > >  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[] = {
> > >  	{"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 to
> > 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 when
> > 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.
> 
> [Moore, Robert]
> 
> There should be no problem with this change concerning older machines. The
> firmware on these machines will simply never call _OSI with any strings newer than
> when the firmware was written -- including this new one.
> 
> 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 until newer
kernels.

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