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@xxxxxxxxx>
---
Documentation/kernel-parameters.txt | 5 ++++-
arch/x86/kernel/acpi/sleep.c | 2 ++
drivers/acpi/sleep.c | 29 +++++++++++++++++------------
include/linux/acpi.h | 1 +
4 files changed, 24 insertions(+), 13 deletions(-)
Index: linux-2.6/drivers/acpi/sleep.c
===================================================================
--- linux-2.6.orig/drivers/acpi/sleep.c
+++ linux-2.6/drivers/acpi/sleep.c
@@ -81,6 +81,23 @@ static int acpi_sleep_prepare(u32 acpi_s
#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[] = {
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
@@ -162,6 +162,8 @@ static int __init acpi_sleep_setup(char
#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");
Index: linux-2.6/include/linux/acpi.h
===================================================================
--- linux-2.6.orig/include/linux/acpi.h
+++ linux-2.6/include/linux/acpi.h
@@ -251,6 +251,7 @@ int acpi_check_mem_region(resource_size_
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 {
Index: linux-2.6/Documentation/kernel-parameters.txt
===================================================================
--- linux-2.6.orig/Documentation/kernel-parameters.txt
+++ linux-2.6/Documentation/kernel-parameters.txt
@@ -240,7 +240,7 @@ and is between 256 and 4096 characters.
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.
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
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