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path: root/drivers/acpi/acpi_pad.c
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Diffstat (limited to 'drivers/acpi/acpi_pad.c')
-rw-r--r--drivers/acpi/acpi_pad.c36
1 files changed, 24 insertions, 12 deletions
diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
index d269a8f3329c..446aced33aff 100644
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -46,6 +46,8 @@ static unsigned long power_saving_mwait_eax;
static unsigned char tsc_detected_unstable;
static unsigned char tsc_marked_unstable;
+static unsigned char lapic_detected_unstable;
+static unsigned char lapic_marked_unstable;
static void power_saving_mwait_init(void)
{
@@ -75,9 +77,6 @@ static void power_saving_mwait_init(void)
power_saving_mwait_eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) |
(highest_subcstate - 1);
- for_each_online_cpu(i)
- clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ON, &i);
-
#if defined(CONFIG_GENERIC_TIME) && defined(CONFIG_X86)
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
@@ -86,13 +85,15 @@ static void power_saving_mwait_init(void)
* AMD Fam10h TSC will tick in all
* C/P/S0/S1 states when this bit is set.
*/
- if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
- return;
-
- /*FALL THROUGH*/
+ if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
+ tsc_detected_unstable = 1;
+ if (!boot_cpu_has(X86_FEATURE_ARAT))
+ lapic_detected_unstable = 1;
+ break;
default:
- /* TSC could halt in idle */
+ /* TSC & LAPIC could halt in idle */
tsc_detected_unstable = 1;
+ lapic_detected_unstable = 1;
}
#endif
}
@@ -180,10 +181,20 @@ static int power_saving_thread(void *data)
mark_tsc_unstable("TSC halts in idle");
tsc_marked_unstable = 1;
}
+ if (lapic_detected_unstable && !lapic_marked_unstable) {
+ int i;
+ /* LAPIC could halt in idle, so notify users */
+ for_each_online_cpu(i)
+ clockevents_notify(
+ CLOCK_EVT_NOTIFY_BROADCAST_ON,
+ &i);
+ lapic_marked_unstable = 1;
+ }
local_irq_disable();
cpu = smp_processor_id();
- clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
- &cpu);
+ if (lapic_marked_unstable)
+ clockevents_notify(
+ CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
stop_critical_timings();
__monitor((void *)&current_thread_info()->flags, 0, 0);
@@ -192,8 +203,9 @@ static int power_saving_thread(void *data)
__mwait(power_saving_mwait_eax, 1);
start_critical_timings();
- clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT,
- &cpu);
+ if (lapic_marked_unstable)
+ clockevents_notify(
+ CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
local_irq_enable();
if (jiffies > expire_time) {