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ACPI: Unconditionally set SCI_EN on resume
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The ACPI spec tells us that the firmware will reenable SCI_EN on resume.
Reality disagrees in some cases. The ACPI spec tells us that the only way
to set SCI_EN is via an SMM call.
https://bugzilla.kernel.org/show_bug.cgi?id=13745 shows us that doing so
may break machines. Tracing the ACPI calls made by Windows shows that it
unconditionally sets SCI_EN on resume with a direct register write, and
therefore the overwhelming probability is that everything is fine with
this behaviour.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
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Matthew Garrett authored and Len Brown committed May 12, 2010
1 parent b430acb commit b6dacf6
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Showing 3 changed files with 2 additions and 158 deletions.
2 changes: 0 additions & 2 deletions arch/x86/kernel/acpi/sleep.c
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Original file line number Diff line number Diff line change
Expand Up @@ -162,8 +162,6 @@ 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");
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157 changes: 2 additions & 155 deletions drivers/acpi/sleep.c
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Original file line number Diff line number Diff line change
Expand Up @@ -80,22 +80,6 @@ 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
Expand Down Expand Up @@ -253,11 +237,8 @@ static int acpi_suspend_enter(suspend_state_t pm_state)
break;
}

/* If ACPI is not enabled by the BIOS, we need to enable it here. */
if (set_sci_en_on_resume)
acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1);
else
acpi_enable();
/* This violates the spec but is required for bug compatibility. */
acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1);

/* Reprogram control registers and execute _BFS */
acpi_leave_sleep_state_prep(acpi_state);
Expand Down Expand Up @@ -346,12 +327,6 @@ static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
return 0;
}

static int __init init_set_sci_en_on_resume(const struct dmi_system_id *d)
{
set_sci_en_on_resume = true;
return 0;
}

static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
{
.callback = init_old_suspend_ordering,
Expand All @@ -370,22 +345,6 @@ static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Apple MacBook 1,1",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "MacBook1,1"),
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Apple MacMini 1,1",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Macmini1,1"),
},
},
{
.callback = init_old_suspend_ordering,
.ident = "Asus Pundit P1-AH2 (M2N8L motherboard)",
.matches = {
Expand All @@ -394,94 +353,6 @@ static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Toshiba Satellite L300",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
DMI_MATCH(DMI_PRODUCT_NAME, "Satellite L300"),
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Hewlett-Packard HP G7000 Notebook PC",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
DMI_MATCH(DMI_PRODUCT_NAME, "HP G7000 Notebook PC"),
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Hewlett-Packard HP Pavilion dv3 Notebook PC",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion dv3 Notebook PC"),
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Hewlett-Packard Pavilion dv4",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion dv4"),
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Hewlett-Packard Pavilion dv7",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion dv7"),
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Hewlett-Packard Compaq Presario C700 Notebook PC",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
DMI_MATCH(DMI_PRODUCT_NAME, "Compaq Presario C700 Notebook PC"),
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Hewlett-Packard Compaq Presario CQ40 Notebook PC",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
DMI_MATCH(DMI_PRODUCT_NAME, "Compaq Presario CQ40 Notebook PC"),
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Lenovo ThinkPad T410",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T410"),
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Lenovo ThinkPad T510",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T510"),
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Lenovo ThinkPad W510",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad W510"),
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Lenovo ThinkPad X201[s]",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201"),
},
},
{
.callback = init_old_suspend_ordering,
.ident = "Panasonic CF51-2L",
.matches = {
Expand All @@ -490,30 +361,6 @@ static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
DMI_MATCH(DMI_BOARD_NAME, "CF51-2L"),
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Dell Studio 1558",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Studio 1558"),
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Dell Studio 1557",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Studio 1557"),
},
},
{
.callback = init_set_sci_en_on_resume,
.ident = "Dell Studio 1555",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Studio 1555"),
},
},
{},
};
#endif /* CONFIG_SUSPEND */
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1 change: 0 additions & 1 deletion include/linux/acpi.h
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Original file line number Diff line number Diff line change
Expand Up @@ -251,7 +251,6 @@ 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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