[PATCH] don't select EFI from certain special ACPI drivers

[PATCH] don't select EFI from certain special ACPI drivers

[Jan Beulich]

Commit 7ea6c6c1 ("Move cper.c from drivers/acpi/apei to
drivers/firmware/efi") results in CONFIG_EFI being enabled even when
the user doesn't want this. Since ACPI APEI used to build fine without
UEFI (and as far as I know also has no functional depency on it), at
least in that case using a reverse dependency is wrong (and a straight
one isn't needed).

Whether the same is true for ACPI_EXTLOG I don't know - if there is a
functional dependency, it should depend on EFI rather than selecting
it. It certainly has (currently) no build dependency.

Adjust Kconfig and build logic so that the bad dependency gets avoided.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
---
 drivers/acpi/Kconfig          |    1 -
 drivers/acpi/apei/Kconfig     |    1 -
 drivers/firmware/Makefile     |    1 +
 drivers/firmware/efi/Kconfig  |    6 +++---
 drivers/firmware/efi/Makefile |    2 +-
 5 files changed, 5 insertions(+), 6 deletions(-)

--- 3.13-rc4/drivers/acpi/Kconfig
+++ 3.13-rc4-ACPI-CPER-no-EFI/drivers/acpi/Kconfig
@@ -348,7 +348,6 @@ source "drivers/acpi/apei/Kconfig"
 config ACPI_EXTLOG
 	tristate "Extended Error Log support"
 	depends on X86_MCE && X86_LOCAL_APIC
-	select EFI
 	select UEFI_CPER
 	default n
 	help
--- 3.13-rc4/drivers/acpi/apei/Kconfig
+++ 3.13-rc4-ACPI-CPER-no-EFI/drivers/acpi/apei/Kconfig
@@ -2,7 +2,6 @@ config ACPI_APEI
 	bool "ACPI Platform Error Interface (APEI)"
 	select MISC_FILESYSTEMS
 	select PSTORE
-	select EFI
 	select UEFI_CPER
 	depends on X86
 	help
--- 3.13-rc4/drivers/firmware/Makefile
+++ 3.13-rc4-ACPI-CPER-no-EFI/drivers/firmware/Makefile
@@ -14,3 +14,4 @@ obj-$(CONFIG_FIRMWARE_MEMMAP)	+= memmap.
 
 obj-$(CONFIG_GOOGLE_FIRMWARE)	+= google/
 obj-$(CONFIG_EFI)		+= efi/
+obj-$(CONFIG_UEFI_CPER)		+= efi/
--- 3.13-rc4/drivers/firmware/efi/Kconfig
+++ 3.13-rc4-ACPI-CPER-no-EFI/drivers/firmware/efi/Kconfig
@@ -36,7 +36,7 @@ config EFI_VARS_PSTORE_DEFAULT_DISABLE
 	  backend for pstore by default. This setting can be overridden
 	  using the efivars module's pstore_disable parameter.
 
-config UEFI_CPER
-	def_bool n
-
 endmenu
+
+config UEFI_CPER
+	bool
--- 3.13-rc4/drivers/firmware/efi/Makefile
+++ 3.13-rc4-ACPI-CPER-no-EFI/drivers/firmware/efi/Makefile
@@ -1,7 +1,7 @@
 #
 # Makefile for linux kernel
 #
-obj-y					+= efi.o vars.o
+obj-$(CONFIG_EFI)			+= efi.o vars.o
 obj-$(CONFIG_EFI_VARS)			+= efivars.o
 obj-$(CONFIG_EFI_VARS_PSTORE)		+= efi-pstore.o
 obj-$(CONFIG_UEFI_CPER)			+= cper.o

RE: [PATCH] don't select EFI from certain special ACPI drivers

[Luck, Tony]

> Adjust Kconfig and build logic so that the bad dependency gets avoided.

Has this been exposed to a randconfig test robot?  Moving cper.c has already
dropped a few e-mails into my mailbox ... I'm now wary about the corner cases.

-Tony

RE: [PATCH] don't select EFI from certain special ACPI drivers

[Jan Beulich]

>>> On 17.12.13 at 00:04, "Luck, Tony" <tony.luck@intel.com> wrote:
>>  Adjust Kconfig and build logic so that the bad dependency gets avoided.
> 
> Has this been exposed to a randconfig test robot?  Moving cper.c has already
> dropped a few e-mails into my mailbox ... I'm now wary about the corner 
> cases.

No, it hasn't. But I explicitly checked the relevant EFI=n and EFI=y
cases.

Jan

RE: [PATCH] don't select EFI from certain special ACPI drivers

[Luck, Tony]

> No, it hasn't. But I explicitly checked the relevant EFI=n and EFI=y
> cases.

Jan,

I pushed your patch into my "next" tree - the robots will notice soon and send
us e-mail if they find any issues.

-Tony

RE: [PATCH] don't select EFI from certain special ACPI drivers

[Jan Beulich]

>>> On 17.12.13 at 23:34, "Luck, Tony" <tony.luck@intel.com> wrote:
>>  No, it hasn't. But I explicitly checked the relevant EFI=n and EFI=y
>> cases.
> 
> I pushed your patch into my "next" tree - the robots will notice soon and 
> send us e-mail if they find any issues.

Thanks, Tony. I'm afraid though that fixing this only in 3.14 would
be a little late: Any "select" in a Kconfig results in the user not being
asked again when that "select" goes away, so people having got EFI
forcibly enabled in 3.13 and updating their configs to 3.14 would
then need to remember to manually disable CONFIG_EFI again (of
course that's already true for anyone using 3.13-rc?, but those
should mostly be people more knowledgeable than folks just
consuming final releases).

I think it should generally be the exception to "select" options that
have visible prompts (i.e. are user configurable).

Jan

Re: [PATCH] don't select EFI from certain special ACPI drivers

[Tony Luck]

On Wed, Dec 18, 2013 at 12:04 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>> On 17.12.13 at 23:34, "Luck, Tony" <tony.luck@intel.com> wrote:
>>>  No, it hasn't. But I explicitly checked the relevant EFI=n and EFI=y
>>> cases.
>>
>> I pushed your patch into my "next" tree - the robots will notice soon and
>> send us e-mail if they find any issues.
>
> Thanks, Tony. I'm afraid though that fixing this only in 3.14 would
> be a little late: Any "select" in a Kconfig results in the user not being
> asked again when that "select" goes away, so people having got EFI
> forcibly enabled in 3.13 and updating their configs to 3.14 would
> then need to remember to manually disable CONFIG_EFI again (of
> course that's already true for anyone using 3.13-rc?, but those
> should mostly be people more knowledgeable than folks just
> consuming final releases).
>
> I think it should generally be the exception to "select" options that
> have visible prompts (i.e. are user configurable).

Ingo: Jan makes a good point that people running "make oldconfig"
may get suckered into selecting CONFIG_EFI when they don't really
need it.  I've not seen any complaints from the robot randconfig testers,
so this patch is:

Acked-by: Tony Luck <tony.luck@intel.com>

Can you push it to Linus before 3.13-final releases?

-Tony

Re: [PATCH] don't select EFI from certain special ACPI drivers

[Ingo Molnar]

* Tony Luck <tony.luck@intel.com> wrote:

> On Wed, Dec 18, 2013 at 12:04 AM, Jan Beulich <JBeulich@suse.com> wrote:
> >>>> On 17.12.13 at 23:34, "Luck, Tony" <tony.luck@intel.com> wrote:
> >>>  No, it hasn't. But I explicitly checked the relevant EFI=n and EFI=y
> >>> cases.
> >>
> >> I pushed your patch into my "next" tree - the robots will notice soon and
> >> send us e-mail if they find any issues.
> >
> > Thanks, Tony. I'm afraid though that fixing this only in 3.14 would
> > be a little late: Any "select" in a Kconfig results in the user not being
> > asked again when that "select" goes away, so people having got EFI
> > forcibly enabled in 3.13 and updating their configs to 3.14 would
> > then need to remember to manually disable CONFIG_EFI again (of
> > course that's already true for anyone using 3.13-rc?, but those
> > should mostly be people more knowledgeable than folks just
> > consuming final releases).
> >
> > I think it should generally be the exception to "select" options that
> > have visible prompts (i.e. are user configurable).
> 
> Ingo: Jan makes a good point that people running "make oldconfig"
> may get suckered into selecting CONFIG_EFI when they don't really
> need it.  I've not seen any complaints from the robot randconfig testers,
> so this patch is:
> 
> Acked-by: Tony Luck <tony.luck@intel.com>
> 
> Can you push it to Linus before 3.13-final releases?

Ok, agreed, I've queued it up in the tip:x86/urgent tree.

Thanks,

	Ingo

[tip:x86/urgent] x86/efi: Don' t select EFI from certain special ACPI drivers

[tip-bot for Jan Beulich]

Commit-ID:  fce7d3bfc0ae70ca2a57868f2a9708b13185fd1f
Gitweb:     http://git.kernel.org/tip/fce7d3bfc0ae70ca2a57868f2a9708b13185fd1f
Author:     Jan Beulich <JBeulich@suse.com>
AuthorDate: Mon, 16 Dec 2013 14:39:40 +0000
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 19 Dec 2013 21:32:46 +0100

x86/efi: Don't select EFI from certain special ACPI drivers

Commit 7ea6c6c1 ("Move cper.c from drivers/acpi/apei to
drivers/firmware/efi") results in CONFIG_EFI being enabled even
when the user doesn't want this. Since ACPI APEI used to build
fine without UEFI (and as far as I know also has no functional
depency on it), at least in that case using a reverse dependency
is wrong (and a straight one isn't needed).

Whether the same is true for ACPI_EXTLOG I don't know - if there
is a functional dependency, it should depend on EFI rather than
selecting it. It certainly has (currently) no build dependency.

Adjust Kconfig and build logic so that the bad dependency gets
avoided.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/52AF1EBC020000780010DBF9@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/acpi/Kconfig          | 1 -
 drivers/acpi/apei/Kconfig     | 1 -
 drivers/firmware/Makefile     | 1 +
 drivers/firmware/efi/Kconfig  | 6 +++---
 drivers/firmware/efi/Makefile | 2 +-
 5 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 5d92485..4770de5 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -348,7 +348,6 @@ source "drivers/acpi/apei/Kconfig"
 config ACPI_EXTLOG
 	tristate "Extended Error Log support"
 	depends on X86_MCE && X86_LOCAL_APIC
-	select EFI
 	select UEFI_CPER
 	default n
 	help
diff --git a/drivers/acpi/apei/Kconfig b/drivers/acpi/apei/Kconfig
index 786294b..3650b21 100644
--- a/drivers/acpi/apei/Kconfig
+++ b/drivers/acpi/apei/Kconfig
@@ -2,7 +2,6 @@ config ACPI_APEI
 	bool "ACPI Platform Error Interface (APEI)"
 	select MISC_FILESYSTEMS
 	select PSTORE
-	select EFI
 	select UEFI_CPER
 	depends on X86
 	help
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 299fad6..5373dc5 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -14,3 +14,4 @@ obj-$(CONFIG_FIRMWARE_MEMMAP)	+= memmap.o
 
 obj-$(CONFIG_GOOGLE_FIRMWARE)	+= google/
 obj-$(CONFIG_EFI)		+= efi/
+obj-$(CONFIG_UEFI_CPER)		+= efi/
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index 3150aa4..6aecbc8 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -36,7 +36,7 @@ config EFI_VARS_PSTORE_DEFAULT_DISABLE
 	  backend for pstore by default. This setting can be overridden
 	  using the efivars module's pstore_disable parameter.
 
-config UEFI_CPER
-	def_bool n
-
 endmenu
+
+config UEFI_CPER
+	bool
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index 9ba156d..6c2a41e 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -1,7 +1,7 @@
 #
 # Makefile for linux kernel
 #
-obj-y					+= efi.o vars.o
+obj-$(CONFIG_EFI)			+= efi.o vars.o
 obj-$(CONFIG_EFI_VARS)			+= efivars.o
 obj-$(CONFIG_EFI_VARS_PSTORE)		+= efi-pstore.o
 obj-$(CONFIG_UEFI_CPER)			+= cper.o