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authorLuca Tettamanti <kronos.it@gmail.com>2009-03-30 00:01:27 +0200
committerLen Brown <len.brown@intel.com>2009-04-02 18:57:46 -0400
commit7e90560c50f754d65884e251e94c1efa2a4b5784 (patch)
tree97ae68b0ae4edaebf3de66716759fc09a97deff6
parent8e0ee43bc2c3e19db56a4adaa9a9b04ce885cd84 (diff)
ACPI: acpi_enforce_resource=strict by default
Enforce strict resource checking - disallowing access by native drivers to IO ports and memory regions claimed by ACPI firmware. The patch is mainly aimed to block native hwmon drivers from touching monitoring chips that ACPI thinks it own. If this causes a regression, boot with "acpi_enforce_resources=lax" which was the previous default. http://bugzilla.kernel.org/show_bug.cgi?id=12376 http://bugzilla.kernel.org/show_bug.cgi?id=12541 Signed-off-by: Luca Tettamanti <kronos.it@gmail.com> Acked-by: Pavel Machek <pavel@suse.cz> Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Len Brown <len.brown@intel.com>
-rw-r--r--Documentation/kernel-parameters.txt16
-rw-r--r--drivers/acpi/osl.c6
2 files changed, 19 insertions, 3 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 54f21a5c262b..7068d0bc47c5 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -258,6 +258,22 @@ and is between 256 and 4096 characters. It is defined in the file
to assume that this machine's pmtimer latches its value
and always returns good values.
+ acpi_enforce_resources= [ACPI]
+ { strict | lax | no }
+ Check for resource conflicts between native drivers
+ and ACPI OperationRegions (SystemIO and SystemMemory
+ only). IO ports and memory declared in ACPI might be
+ used by the ACPI subsystem in arbitrary AML code and
+ can interfere with legacy drivers.
+ strict (default): access to resources claimed by ACPI
+ is denied; legacy drivers trying to access reserved
+ resources will fail to bind to device using them.
+ lax: access to resources claimed by ACPI is allowed;
+ legacy drivers trying to access reserved resources
+ will bind successfully but a warning message is logged.
+ no: ACPI OperationRegions are not marked as reserved,
+ no further checks are performed.
+
agp= [AGP]
{ off | try_unsupported }
off: disable AGP support
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 1e35f342957c..f50ca1ea80c3 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -1063,9 +1063,9 @@ __setup("acpi_wake_gpes_always_on", acpi_wake_gpes_always_on_setup);
* in arbitrary AML code and can interfere with legacy drivers.
* acpi_enforce_resources= can be set to:
*
- * - strict (2)
+ * - strict (default) (2)
* -> further driver trying to access the resources will not load
- * - lax (default) (1)
+ * - lax (1)
* -> further driver trying to access the resources will load, but you
* get a system message that something might go wrong...
*
@@ -1077,7 +1077,7 @@ __setup("acpi_wake_gpes_always_on", acpi_wake_gpes_always_on_setup);
#define ENFORCE_RESOURCES_LAX 1
#define ENFORCE_RESOURCES_NO 0
-static unsigned int acpi_enforce_resources = ENFORCE_RESOURCES_LAX;
+static unsigned int acpi_enforce_resources = ENFORCE_RESOURCES_STRICT;
static int __init acpi_enforce_resources_setup(char *str)
{