ACPI: Unconditionally set SCI_EN on resume
authorMatthew Garrett <mjg@redhat.com>
Tue, 11 May 2010 17:49:25 +0000 (13:49 -0400)
committerLen Brown <len.brown@intel.com>
Wed, 12 May 2010 05:12:18 +0000 (01:12 -0400)
commitb6dacf63e9fb2e7a1369843d6cef332f76fca6a3
tree4b7fbde0071172718270a5646f1168edb6d07023
parentb430acbd7c4b919886fa7fd92eeb7a695f1940d3
ACPI: Unconditionally set SCI_EN on resume

The ACPI spec tells us that the firmware will reenable SCI_EN on resume.
Reality disagrees in some cases. The ACPI spec tells us that the only way
to set SCI_EN is via an SMM call.
https://bugzilla.kernel.org/show_bug.cgi?id=13745 shows us that doing so
may break machines. Tracing the ACPI calls made by Windows shows that it
unconditionally sets SCI_EN on resume with a direct register write, and
therefore the overwhelming probability is that everything is fine with
this behaviour.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
arch/x86/kernel/acpi/sleep.c
drivers/acpi/sleep.c
include/linux/acpi.h