ACPI hibernate: Introduce new kernel parameter acpi_sleep=s4_nonvs

On some machines it may be necessary to disable the saving/restoring
of the ACPI NVS memory region during hibernation/resume.  For this
purpose, introduce new ACPI kernel command line option
acpi_sleep=s4_nonvs.

Based on a patch by Zhang Rui.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@tuxonice.net>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index e0f346d201ed..1d089eeff3cf 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -149,7 +149,8 @@ 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, s4_nohwsig, old_ordering }
+                        Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
+                                  old_ordering, s4_nonvs }
                         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.
@@ -159,6 +160,8 @@ and is between 256 and 4096 characters. It is defined in the file
                         control method, wrt putting devices into low power
                         states, to be enforced (the ACPI 2.0 ordering of _PTS is
                         used by default).
+                        s4_nonvs prevents the kernel from saving/restoring the
+                        ACPI NVS memory during hibernation.
 
         acpi_sci=       [HW,ACPI] ACPI System Control Interrupt trigger mode
                         Format: { level | edge | high | low }