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author | Zhang Rui <rui.zhang@intel.com> | 2009-12-30 15:36:42 +0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-05-12 14:57:11 -0700 |
commit | 0c468b435fa14744fc25ad999d357afcba710954 (patch) | |
tree | a5e05e8f0091f595224bc321f81c1db6981118e0 | |
parent | 637f3674cbecf9bd2073276d16ebf31b8775bf7b (diff) | |
download | lwn-0c468b435fa14744fc25ad999d357afcba710954.tar.gz lwn-0c468b435fa14744fc25ad999d357afcba710954.zip |
ACPI: introduce kernel parameter acpi_sleep=sci_force_enable
commit d7f0eea9e431e1b8b0742a74db1a9490730b2a25 upstream.
Introduce kernel parameter acpi_sleep=sci_force_enable
some laptop requires SCI_EN being set directly on resume,
or else they hung somewhere in the resume code path.
We already have a blacklist for these laptops but we still need
this option, especially when debugging some suspend/resume problems,
in case there are systems that need this workaround and are not yet
in the blacklist.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r-- | Documentation/kernel-parameters.txt | 5 | ||||
-rw-r--r-- | arch/x86/kernel/acpi/sleep.c | 2 | ||||
-rw-r--r-- | drivers/acpi/sleep.c | 29 | ||||
-rw-r--r-- | include/linux/acpi.h | 1 |
4 files changed, 24 insertions, 13 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 345c3998ec42..5f6aa11fb457 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -241,7 +241,7 @@ and is between 256 and 4096 characters. It is defined in the file acpi_sleep= [HW,ACPI] Sleep options Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, - old_ordering, s4_nonvs } + old_ordering, s4_nonvs, sci_force_enable } See Documentation/power/video.txt for information on s3_bios and s3_mode. s3_beep is for debugging; it makes the PC's speaker beep @@ -254,6 +254,9 @@ and is between 256 and 4096 characters. It is defined in the file of _PTS is used by default). s4_nonvs prevents the kernel from saving/restoring the ACPI NVS memory during hibernation. + sci_force_enable causes the kernel to set SCI_EN directly + on resume from S1/S3 (which is against the ACPI spec, + but some broken systems don't work without it). acpi_use_timer_override [HW,ACPI] Use timer override. For some broken Nvidia NF5 boards diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c index ca93638ba430..8b8573473903 100644 --- a/arch/x86/kernel/acpi/sleep.c +++ b/arch/x86/kernel/acpi/sleep.c @@ -162,6 +162,8 @@ static int __init acpi_sleep_setup(char *str) #endif if (strncmp(str, "old_ordering", 12) == 0) acpi_old_suspend_ordering(); + if (strncmp(str, "sci_force_enable", 16) == 0) + acpi_set_sci_en_on_resume(); str = strchr(str, ','); if (str != NULL) str += strspn(str, ", \t"); diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c index 5f2c379ab7bf..79d33d908b5a 100644 --- a/drivers/acpi/sleep.c +++ b/drivers/acpi/sleep.c @@ -81,6 +81,23 @@ static int acpi_sleep_prepare(u32 acpi_state) #ifdef CONFIG_ACPI_SLEEP static u32 acpi_target_sleep_state = ACPI_STATE_S0; /* + * According to the ACPI specification the BIOS should make sure that ACPI is + * enabled and SCI_EN bit is set on wake-up from S1 - S3 sleep states. Still, + * some BIOSes don't do that and therefore we use acpi_enable() to enable ACPI + * on such systems during resume. Unfortunately that doesn't help in + * particularly pathological cases in which SCI_EN has to be set directly on + * resume, although the specification states very clearly that this flag is + * owned by the hardware. The set_sci_en_on_resume variable will be set in such + * cases. + */ +static bool set_sci_en_on_resume; + +void __init acpi_set_sci_en_on_resume(void) +{ + set_sci_en_on_resume = true; +} + +/* * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the * user to request that behavior by using the 'acpi_old_suspend_ordering' * kernel command line option that causes the following variable to be set. @@ -170,18 +187,6 @@ static void acpi_pm_end(void) #endif /* CONFIG_ACPI_SLEEP */ #ifdef CONFIG_SUSPEND -/* - * According to the ACPI specification the BIOS should make sure that ACPI is - * enabled and SCI_EN bit is set on wake-up from S1 - S3 sleep states. Still, - * some BIOSes don't do that and therefore we use acpi_enable() to enable ACPI - * on such systems during resume. Unfortunately that doesn't help in - * particularly pathological cases in which SCI_EN has to be set directly on - * resume, although the specification states very clearly that this flag is - * owned by the hardware. The set_sci_en_on_resume variable will be set in such - * cases. - */ -static bool set_sci_en_on_resume; - extern void do_suspend_lowlevel(void); static u32 acpi_suspend_states[] = { diff --git a/include/linux/acpi.h b/include/linux/acpi.h index c010b94625c2..07432a144204 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -251,6 +251,7 @@ int acpi_check_mem_region(resource_size_t start, resource_size_t n, void __init acpi_no_s4_hw_signature(void); void __init acpi_old_suspend_ordering(void); void __init acpi_s4_no_nvs(void); +void __init acpi_set_sci_en_on_resume(void); #endif /* CONFIG_PM_SLEEP */ struct acpi_osc_context { |