Commit 741d8128 authored by Lv Zheng's avatar Lv Zheng Committed by Rafael J. Wysocki
Browse files

ACPI: Add facility to remove all _OSI strings 



This patch changes the "acpi_osi=" boot parameter implementation so
that:
1. "acpi_osi=!" can be used to disable all _OSI OS vendor strings by
   default.  It is meaningless to specify "acpi_osi=!" multiple
   times as it can only affect the default state of the target _OSI
   strings.
2. "acpi_osi=!*" can be used to remove all _OSI OS vendor strings
   and all _OSI feature group strings.  It is useful to specify
   "acpi_osi=!*" multiple times through kernel command line to
   override the current state of the target _OSI strings.

Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
Reviewed-by: default avatarZhang Rui <rui.zhang@intel.com>
Acked-by: default avatarLen Brown <len.brown@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 5dc17986

Documentation/kernel-parameters.txt

+27 −1
Original line number Diff line number Diff line
@@ -237,6 +237,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
	acpi_osi=	[HW,ACPI] Modify list of supported OS interface strings

			acpi_osi="string1"	# add string1

			acpi_osi="!string2"	# remove string2

			acpi_osi=!*		# remove all strings

			acpi_osi=!		# disable all built-in OS vendor

						  strings

			acpi_osi=		# disable all strings
@@ -248,7 +249,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
			it cannot affect the default state of the feature group

			strings and the current state of the OS vendor strings,

			specifying it multiple times through kernel command line

			is meaningless.

			is meaningless.  This command is useful when one do not

			care about the state of the feature group strings which

			should be controlled by the OSPM.

			Examples:

			  1. 'acpi_osi=! acpi_osi="Windows 2000"' is equivalent

			     to 'acpi_osi="Windows 2000" acpi_osi=!', they all
@@ -264,6 +267,29 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
			  1. 'acpi_osi=' can make 'CondRefOf(_OSI, Local1)'

			     FALSE.



			'acpi_osi=!*' can be used in combination with single or

			multiple 'acpi_osi="string1"' to support specific

			string(s).  Note that such command can affect the

			current state of both the OS vendor strings and the

			feature group strings, thus specifying it multiple times

			through kernel command line is meaningful.  But it may

			still not able to affect the final state of a string if

			there are quirks related to this string.  This command

			is useful when one want to control the state of the

			feature group strings to debug BIOS issues related to

			the OSPM features.

			Examples:

			  1. 'acpi_osi="Module Device" acpi_osi=!*' can make

			     '_OSI("Module Device")' FALSE.

			  2. 'acpi_osi=!* acpi_osi="Module Device"' can make

			     '_OSI("Module Device")' TRUE.

			  3. 'acpi_osi=! acpi_osi=!* acpi_osi="Windows 2000"' is

			     equivalent to

			     'acpi_osi=!* acpi_osi=! acpi_osi="Windows 2000"'

			     and

			     'acpi_osi=!* acpi_osi="Windows 2000" acpi_osi=!',

			     they all will make '_OSI("Windows 2000")' TRUE.



	acpi_pm_good	[X86]

			Override the pmtimer bug detection: force the kernel

			to assume that this machine's pmtimer latches its value

drivers/acpi/osl.c

+7 −0
Original line number Diff line number Diff line
@@ -1380,6 +1380,13 @@ void __init acpi_osi_setup(char *str) 
		if (*str == '\0') {

			osi_linux.default_disabling = 1;

			return;

		} else if (*str == '*') {

			acpi_update_interfaces(ACPI_DISABLE_ALL_STRINGS);

			for (i = 0; i < OSI_STRING_ENTRIES_MAX; i++) {

				osi = &osi_setup_entries[i];

				osi->enable = false;

			}

			return;

		}

		enable = false;

	}

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