Re: [linux-pm] [PATCH 4/4] ACPI hibernate: Introduce new kernel parameter acpi_sleep=s4_nonvs

Nigel Cunningham
2008-10-22T22:51:37Z

Hi.

On Wed, 2008-10-22 at 22:54 +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
>
> 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>
> Cc: Zhang Rui <rui.zhang@intel.com>
> ---
> 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)

s/13/8/

> + 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 */

Apart from the above,

Acked-by: Nigel Cunningham <nigel@tuxonice.net>