ACPI suspend: Call _PTS before suspending devices

The ACPI 1.0 specification wants us to put devices into low power
states after executing the _PTS global control method, while ACPI
2.0 and later want us to do that in the reverse order.  The current
suspend code follows ACPI 2.0 in that respect which causes some
ACPI 1.0x systems to hang during suspend (ref.
http://bugzilla.kernel.org/show_bug.cgi?id=9528).

Make the suspend code execute _PTS before putting devices into low
power states (ie. in accordance with ACPI 1.0x) and provide a command
line option to override the default if need be.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 92c40d174355..cf3868956f1e 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -168,6 +168,11 @@ and is between 256 and 4096 characters. It is defined in the file
         acpi_irq_isa=   [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
                         Format: <irq>,<irq>...
 
+        acpi_new_pts_ordering [HW,ACPI]
+                        Enforce the ACPI 2.0 ordering of the _PTS control
+                        method wrt putting devices into low power states
+                        default: pre ACPI 2.0 ordering of _PTS
+
         acpi_no_auto_ssdt       [HW,ACPI] Disable automatic loading of SSDT
 
         acpi_os_name=   [HW,ACPI] Tell ACPI BIOS the name of the OS