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authorThomas Gleixner <tglx@linutronix.de>2007-09-22 22:29:05 +0000
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-09-22 17:15:34 -0700
commitb04e7bdb984e3b7f62fb7f44146a529f88cc7639 (patch)
tree57fa4b6ab2e6bd20b0a2eed12db2a484e928fe17
parent1f0cff6e4d579ab0fe671c02fcd842694e46b90f (diff)
downloadlinux-2.6.34-ux500-b04e7bdb984e3b7f62fb7f44146a529f88cc7639.tar.gz
ACPI: disable lower idle C-states across suspend/resume
device_suspend() calls ACPI suspend functions, which seems to have undesired side effects on lower idle C-states. It took me some time to realize that especially the VAIO BIOSes (both Andrews jinxed UP and my elfstruck SMP one) show this effect. I'm quite sure that other bug reports against suspend/resume about turning the system into a brick have the same root cause. After fishing in the dark for quite some time, I realized that removing the ACPI processor module before suspend (this removes the lower C-state functionality) made the problem disappear. Interestingly enough the propability of having a bricked box is influenced by various factors (interrupts, size of the ram image, ...). Even adding a bunch of printks in the wrong places made the problem go away. The previous periodic tick implementation simply pampered over the problem, which explains why the dyntick / clockevents changes made this more prominent. We avoid complex functionality during the boot process and we have to do the same during suspend/resume. It is a similar scenario and equaly fragile. Add suspend / resume functions to the ACPI processor code and disable the lower idle C-states across suspend/resume. Fall back to the default idle implementation (halt) instead. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Andrew Morton <akpm@linux-foundation.org> Cc: Len Brown <lenb@kernel.org> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/acpi/processor_core.c2
-rw-r--r--drivers/acpi/processor_idle.c19
-rw-r--r--include/acpi/processor.h2
3 files changed, 22 insertions, 1 deletions
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index 2afb3d2086b..9f11dc296cd 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -102,6 +102,8 @@ static struct acpi_driver acpi_processor_driver = {
.add = acpi_processor_add,
.remove = acpi_processor_remove,
.start = acpi_processor_start,
+ .suspend = acpi_processor_suspend,
+ .resume = acpi_processor_resume,
},
};
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index d9b8af763e1..f18261368e7 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -325,6 +325,23 @@ static void acpi_state_timer_broadcast(struct acpi_processor *pr,
#endif
+/*
+ * Suspend / resume control
+ */
+static int acpi_idle_suspend;
+
+int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
+{
+ acpi_idle_suspend = 1;
+ return 0;
+}
+
+int acpi_processor_resume(struct acpi_device * device)
+{
+ acpi_idle_suspend = 0;
+ return 0;
+}
+
static void acpi_processor_idle(void)
{
struct acpi_processor *pr = NULL;
@@ -355,7 +372,7 @@ static void acpi_processor_idle(void)
}
cx = pr->power.state;
- if (!cx) {
+ if (!cx || acpi_idle_suspend) {
if (pm_idle_save)
pm_idle_save();
else
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index ec3ffdadb4d..99934a999e6 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -320,6 +320,8 @@ int acpi_processor_power_init(struct acpi_processor *pr,
int acpi_processor_cst_has_changed(struct acpi_processor *pr);
int acpi_processor_power_exit(struct acpi_processor *pr,
struct acpi_device *device);
+int acpi_processor_suspend(struct acpi_device * device, pm_message_t state);
+int acpi_processor_resume(struct acpi_device * device);
/* in processor_thermal.c */
int acpi_processor_get_limit_info(struct acpi_processor *pr);