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

Rafael J. Wysocki
2008-10-22T23:05:21Z

On Thursday, 23 of October 2008, Nigel Cunningham wrote:
> 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/

Sure, thanks for catching that (it was a different string in the original
patch).

> > + 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>

Thanks,
Rafael