Commit d7f0eea9 authored by Zhang Rui's avatar Zhang Rui Committed by Len Brown
Browse files

ACPI: introduce kernel parameter acpi_sleep=sci_force_enable 



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: default avatarZhang Rui <rui.zhang@intel.com>
Acked-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 6b7b2849

Documentation/kernel-parameters.txt

+4 −1
Original line number Diff line number Diff line
@@ -240,7 +240,7 @@ 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
@@ -253,6 +253,9 @@ 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

arch/x86/kernel/acpi/sleep.c

+2 −0
Original line number Diff line number Diff line
@@ -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");

drivers/acpi/sleep.c

+17 −12
Original line number Diff line number Diff line
@@ -80,6 +80,23 @@ 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'
@@ -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[] = {

include/linux/acpi.h

+1 −0
Original line number Diff line number Diff line
@@ -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 {

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