diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/acpi/processor_idle.c | 66 |
1 files changed, 47 insertions, 19 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index e34af7772a66..4ea6d8b20d17 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -248,6 +248,48 @@ static void acpi_cstate_enter(struct acpi_processor_cx *cstate) } } +#ifdef ARCH_APICTIMER_STOPS_ON_C3 + +/* + * Some BIOS implementations switch to C3 in the published C2 state. + * This seems to be a common problem on AMD boxen, but other vendors + * are affected too. We pick the most conservative approach: we assume + * that the local APIC stops in both C2 and C3. + */ +static void acpi_timer_check_state(int state, struct acpi_processor *pr, + struct acpi_processor_cx *cx) +{ + struct acpi_processor_power *pwr = &pr->power; + + /* + * Check, if one of the previous states already marked the lapic + * unstable + */ + if (pwr->timer_broadcast_on_state < state) + return; + + if (cx->type >= ACPI_STATE_C2) + pr->power.timer_broadcast_on_state = state; +} + +static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) +{ + cpumask_t mask = cpumask_of_cpu(pr->id); + + if (pr->power.timer_broadcast_on_state < INT_MAX) + on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1); + else + on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1); +} + +#else + +static void acpi_timer_check_state(int state, struct acpi_processor *pr, + struct acpi_processor_cx *cstate) { } +static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { } + +#endif + static void acpi_processor_idle(void) { struct acpi_processor *pr = NULL; @@ -914,11 +956,7 @@ static int acpi_processor_power_verify(struct acpi_processor *pr) unsigned int i; unsigned int working = 0; -#ifdef ARCH_APICTIMER_STOPS_ON_C3 - int timer_broadcast = 0; - cpumask_t mask = cpumask_of_cpu(pr->id); - on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1); -#endif + pr->power.timer_broadcast_on_state = INT_MAX; for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { struct acpi_processor_cx *cx = &pr->power.states[i]; @@ -930,21 +968,14 @@ static int acpi_processor_power_verify(struct acpi_processor *pr) case ACPI_STATE_C2: acpi_processor_power_verify_c2(cx); -#ifdef ARCH_APICTIMER_STOPS_ON_C3 - /* Some AMD systems fake C3 as C2, but still - have timer troubles */ - if (cx->valid && - boot_cpu_data.x86_vendor == X86_VENDOR_AMD) - timer_broadcast++; -#endif + if (cx->valid) + acpi_timer_check_state(i, pr, cx); break; case ACPI_STATE_C3: acpi_processor_power_verify_c3(pr, cx); -#ifdef ARCH_APICTIMER_STOPS_ON_C3 if (cx->valid) - timer_broadcast++; -#endif + acpi_timer_check_state(i, pr, cx); break; } @@ -952,10 +983,7 @@ static int acpi_processor_power_verify(struct acpi_processor *pr) working++; } -#ifdef ARCH_APICTIMER_STOPS_ON_C3 - if (timer_broadcast) - on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1); -#endif + acpi_propagate_timer_broadcast(pr); return (working); } |
