[PATCH 1/2]cpuidle: makes AMD C1E works in acpi_idle

From: Shaohua Li
Date: Tue May 19 2009 - 04:10:01 EST


When AMD C1E is enabled, local APIC timer will stop even in C1. This patch uses
broadcast ipi to replace local APIC timer in C1.

http://bugzilla.kernel.org/show_bug.cgi?id=13233

[ impact: avoid boot hang in AMD CPU with C1E enabled ]

Tested-by: Dmitry Lyzhyn <thisistempbox@xxxxxxxxx>
Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx>
---
drivers/acpi/processor_idle.c | 6 ++++++
1 file changed, 6 insertions(+)

Index: linux/drivers/acpi/processor_idle.c
===================================================================
--- linux.orig/drivers/acpi/processor_idle.c 2009-05-19 09:45:23.000000000 +0800
+++ linux/drivers/acpi/processor_idle.c 2009-05-19 09:56:59.000000000 +0800
@@ -148,6 +148,9 @@ static void acpi_timer_check_state(int s
if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
return;

+ if (boot_cpu_has(X86_FEATURE_AMDC1E))
+ type = ACPI_STATE_C1;
+
/*
* Check, if one of the previous states already marked the lapic
* unstable
@@ -611,6 +614,7 @@ static int acpi_processor_power_verify(s
switch (cx->type) {
case ACPI_STATE_C1:
cx->valid = 1;
+ acpi_timer_check_state(i, pr, cx);
break;

case ACPI_STATE_C2:
@@ -835,6 +839,7 @@ static int acpi_idle_enter_c1(struct cpu
return 0;
}

+ acpi_state_timer_broadcast(pr, cx, 1);
kt1 = ktime_get_real();
acpi_idle_do_entry(cx);
kt2 = ktime_get_real();
@@ -842,6 +847,7 @@ static int acpi_idle_enter_c1(struct cpu

local_irq_enable();
cx->usage++;
+ acpi_state_timer_broadcast(pr, cx, 0);

return idle_time;
}
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