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authorLv Zheng <lv.zheng@intel.com>2016-04-11 10:13:33 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-04-18 23:59:09 +0200
commit5d8813271f8a7c86027afb2ef554f2a5a9ba7c15 (patch)
tree75e3ea3cafe1b4be9ce00a7352ce75ca0c9fb7a4 /drivers/acpi/Kconfig
parentaf06f8b7a102417e93dc57ee7affb9fedcf5d83f (diff)
downloadlinux-5d8813271f8a7c86027afb2ef554f2a5a9ba7c15.tar.bz2
ACPI / tables: Convert initrd table override to table upgrade mechanism
This patch converts the initrd table override mechanism to the table upgrade mechanism by restricting its usage to the tables released with compatibility and more recent revision. This use case has been encouraged by the ACPI specification: 1. OEMID: An OEM-supplied string that identifies the OEM. 2. OEM Table ID: An OEM-supplied string that the OEM uses to identify the particular data table. This field is particularly useful when defining a definition block to distinguish definition block functions. OEM assigns each dissimilar table a new OEM Table Id. 3. OEM Revision: An OEM-supplied revision number. Larger numbers are assumed to be newer revisions. For OEMs, good practices will ensure consistency when assigning OEMID and OEM Table ID fields in any table. The intent of these fields is to allow for a binary control system that support services can use. Because many support function can be automated, it is useful when a tool can programatically determine which table release is a compatible and more recent revision of a prior table on the same OEMID and OEM Table ID. The facility can now be used by the vendors to upgrade wrong tables for bug fixing purpose, thus lockdep disabling taint is not suitable for it and it should be a default 'y' option to implement the spec encouraged use case. Note that, by implementing table upgrade inside of ACPICA itself, it is possible to remove acpi_table_initrd_override() and tables can be upgraded by acpi_install_table() automatically. Though current ACPICA impelentation hasn't implemented this, this patched changes the table flag setting timing to allow this to be implemented in ACPICA without changing the code here. Documentation of initrd override mechanism is upgraded accordingly. Original-by: Octavian Purdila <octavian.purdila@intel.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/Kconfig')
-rw-r--r--drivers/acpi/Kconfig8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 82b96ee8624c..b225c4b9ba14 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -311,12 +311,12 @@ config ACPI_CUSTOM_DSDT
bool
default ACPI_CUSTOM_DSDT_FILE != ""
-config ACPI_INITRD_TABLE_OVERRIDE
- bool "ACPI tables override via initrd"
+config ACPI_TABLE_UPGRADE
+ bool "Allow upgrading ACPI tables via initrd"
depends on BLK_DEV_INITRD && X86
- default n
+ default y
help
- This option provides functionality to override arbitrary ACPI tables
+ This option provides functionality to upgrade arbitrary ACPI tables
via initrd. No functional change if no ACPI tables are passed via
initrd, therefore it's safe to say Y.
See Documentation/acpi/initrd_table_override.txt for details