From: Rafael J. Wysocki <rjw@xxxxxxx>
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@xxxxxxx>
Cc: Zhang Rui <rui.zhang@xxxxxxxxx>
---
Documentation/kernel-parameters.txt | 5 ++++-
arch/x86/kernel/acpi/sleep.c | 2 ++
drivers/acpi/sleep/main.c | 19 +++++++++++++++++--
include/linux/acpi.h | 1 +
4 files changed, 24 insertions(+), 3 deletions(-)
Index: linux-2.6/Documentation/kernel-parameters.txt
===================================================================
--- linux-2.6.orig/Documentation/kernel-parameters.txt
+++ linux-2.6/Documentation/kernel-parameters.txt
@@ -149,7 +149,8 @@ and is between 256 and 4096 characters.
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.
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 }
Index: linux-2.6/arch/x86/kernel/acpi/sleep.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/acpi/sleep.c
+++ linux-2.6/arch/x86/kernel/acpi/sleep.c
@@ -161,6 +161,8 @@ static int __init acpi_sleep_setup(char
#endif
if (strncmp(str, "old_ordering", 12) == 0)
acpi_old_suspend_ordering();
+ if (strncmp(str, "s4_nonvs", 13) == 0)
+ acpi_s4_no_nvs();
str = strchr(str, ',');
if (str != NULL)
str += strspn(str, ", \t");
Index: linux-2.6/drivers/acpi/sleep/main.c
===================================================================
--- linux-2.6.orig/drivers/acpi/sleep/main.c
+++ linux-2.6/drivers/acpi/sleep/main.c
@@ -59,6 +59,20 @@ void __init acpi_old_suspend_ordering(vo
old_suspend_ordering = true;
}
+/*
+ * The ACPI specification wants us to save NVS memory regions during hibernation
+ * and to restore them during the subsequent resume. However, it is not certain
+ * if this mechanism is going to work on all machines, so we allow the user to
+ * disable this mechanism using the 'acpi_sleep=s4_nonvs' kernel command line
+ * option.
+ */
+static bool s4_no_nvs;
+
+void __init acpi_s4_no_nvs(void)
+{
+ s4_no_nvs = true;
+}
+
/**
* acpi_pm_disable_gpes - Disable the GPEs.
*/
@@ -323,7 +337,7 @@ static int acpi_hibernation_begin(void)
{
int error;
- error = hibernate_nvs_alloc();
+ error = s4_no_nvs ? 0 : hibernate_nvs_alloc();
if (!error)
acpi_target_sleep_state = ACPI_STATE_S4;
@@ -411,7 +425,8 @@ static int acpi_hibernation_begin_old(vo
int error = acpi_sleep_prepare(ACPI_STATE_S4);
if (!error) {
- error = hibernate_nvs_alloc();
+ if (!s4_no_nvs)
+ error = hibernate_nvs_alloc();
if (!error)
acpi_target_sleep_state = ACPI_STATE_S4;
}
Index: linux-2.6/include/linux/acpi.h
===================================================================
--- linux-2.6.orig/include/linux/acpi.h
+++ linux-2.6/include/linux/acpi.h
@@ -238,6 +238,7 @@ int acpi_check_mem_region(resource_size_
#ifdef CONFIG_PM_SLEEP
void __init acpi_no_s4_hw_signature(void);
void __init acpi_old_suspend_ordering(void);
+void __init acpi_s4_no_nvs(void);
#endif /* CONFIG_PM_SLEEP */
#else /* CONFIG_ACPI */
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