Suspend-related patches for 2.6.27

ACPI PM: Add possibility to change suspend sequence

There are some systems out there that don't work correctly with
our current suspend/hibernation code ordering.  Provide a workaround
for these systems allowing them to pass 'acpi_sleep=old_ordering' in
the kernel command line so that it will use the pre-ACPI 2.0 ("old")
suspend code ordering.

Unfortunately, this requires us to add a platform hook to the
resuming of devices for recovering the platform in case one of the
device drivers' .suspend() routines returns error code.  Namely,
ACPI 1.0 specifies that _PTS should be called before suspending
devices, but _WAK still should be called before resuming them in
order to undo the changes made by _PTS.  However, if there is an
error during suspending devices, they are automatically resumed
without returning control to the PM core, so the _WAK has to be
called from within device_resume() in that cases.

The patch also reorders and refactors the ACPI suspend/hibernation
code to avoid duplication as far as reasonably possible.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 9cf7b34f2db0..18d793ea0dd3 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -147,10 +147,14 @@ and is between 256 and 4096 characters. It is defined in the file
                         default: 0
 
         acpi_sleep=     [HW,ACPI] Sleep options
-                        Format: { s3_bios, s3_mode, s3_beep }
+                        Format: { s3_bios, s3_mode, s3_beep, old_ordering }
                         See Documentation/power/video.txt for s3_bios and s3_mode.
                         s3_beep is for debugging; it makes the PC's speaker beep
                         as soon as the kernel's real-mode entry point is called.
+                        old_ordering causes the ACPI 1.0 ordering of the _PTS
+                        control method, wrt putting devices into low power
+                        states, to be enforced (the ACPI 2.0 ordering of _PTS is
+                        used by default).
 
         acpi_sci=       [HW,ACPI] ACPI System Control Interrupt trigger mode
                         Format: { level | edge | high | low }