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cpuidle: fix HP nx6125 regression

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Fix for http://bugzilla.kernel.org/show_bug.cgi?id=9355

cpuidle always used to fallback to C2 if there is some bm activity while
entering C3. But, presence of C2 is not always guaranteed. Change cpuidle
algorithm to detect a safe_state to fallback in case of bm_activity and
use that state instead of C2.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Venkatesh Pallipadi 2007-11-19 21:43:22 -05:00 committed by Len Brown
parent 5062911830
commit ddc081a195
3 changed files with 56 additions and 71 deletions
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125
drivers/acpi/processor_idle.c
View file

@ -197,6 +197,19 @@ static inline u32 ticks_elapsed_in_us(u32 t1, u32 t2)
return PM_TIMER_TICKS_TO_US((0xFFFFFFFF - t1) + t2);
}
static void acpi_safe_halt(void)
{
current_thread_info()->status &= ~TS_POLLING;
/*
* TS_POLLING-cleared state must be visible before we
* test NEED_RESCHED:
*/
smp_mb();
if (!need_resched())
safe_halt();
current_thread_info()->status |= TS_POLLING;
}
#ifndef CONFIG_CPU_IDLE
static void
@ -239,19 +252,6 @@ acpi_processor_power_activate(struct acpi_processor *pr,
return;
}
static void acpi_safe_halt(void)
{
current_thread_info()->status &= ~TS_POLLING;
/*
* TS_POLLING-cleared state must be visible before we
* test NEED_RESCHED:
*/
smp_mb();
if (!need_resched())
safe_halt();
current_thread_info()->status |= TS_POLLING;
}
static atomic_t c3_cpu_count;
/* Common C-state entry for C2, C3, .. */
@ -1385,15 +1385,7 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev,
if (pr->flags.bm_check)
acpi_idle_update_bm_rld(pr, cx);
current_thread_info()->status &= ~TS_POLLING;
/*
* TS_POLLING-cleared state must be visible before we test
* NEED_RESCHED:
*/
smp_mb();
if (!need_resched())
safe_halt();
current_thread_info()->status |= TS_POLLING;
acpi_safe_halt();
cx->usage++;
@ -1493,6 +1485,15 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
if (acpi_idle_suspend)
return(acpi_idle_enter_c1(dev, state));
if (acpi_idle_bm_check()) {
if (dev->safe_state) {
return dev->safe_state->enter(dev, dev->safe_state);
} else {
acpi_safe_halt();
return 0;
}
}
local_irq_disable();
current_thread_info()->status &= ~TS_POLLING;
/*
@ -1515,49 +1516,39 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
*/
acpi_state_timer_broadcast(pr, cx, 1);
if (acpi_idle_bm_check()) {
cx = pr->power.bm_state;
acpi_idle_update_bm_rld(pr, cx);
acpi_idle_update_bm_rld(pr, cx);
/*
* disable bus master
* bm_check implies we need ARB_DIS
* !bm_check implies we need cache flush
* bm_control implies whether we can do ARB_DIS
*
* That leaves a case where bm_check is set and bm_control is
* not set. In that case we cannot do much, we enter C3
* without doing anything.
*/
if (pr->flags.bm_check && pr->flags.bm_control) {
spin_lock(&c3_lock);
c3_cpu_count++;
/* Disable bus master arbitration when all CPUs are in C3 */
if (c3_cpu_count == num_online_cpus())
acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
spin_unlock(&c3_lock);
} else if (!pr->flags.bm_check) {
ACPI_FLUSH_CPU_CACHE();
}
t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
acpi_idle_do_entry(cx);
t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
} else {
acpi_idle_update_bm_rld(pr, cx);
t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
acpi_idle_do_entry(cx);
t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
/*
* disable bus master
* bm_check implies we need ARB_DIS
* !bm_check implies we need cache flush
* bm_control implies whether we can do ARB_DIS
*
* That leaves a case where bm_check is set and bm_control is
* not set. In that case we cannot do much, we enter C3
* without doing anything.
*/
if (pr->flags.bm_check && pr->flags.bm_control) {
spin_lock(&c3_lock);
c3_cpu_count++;
/* Disable bus master arbitration when all CPUs are in C3 */
if (c3_cpu_count == num_online_cpus())
acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
spin_unlock(&c3_lock);
} else if (!pr->flags.bm_check) {
ACPI_FLUSH_CPU_CACHE();
}
t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
acpi_idle_do_entry(cx);
t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
/* Re-enable bus master arbitration */
if (pr->flags.bm_check && pr->flags.bm_control) {
spin_lock(&c3_lock);
acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
c3_cpu_count--;
spin_unlock(&c3_lock);
}
/* Re-enable bus master arbitration */
if (pr->flags.bm_check && pr->flags.bm_control) {
spin_lock(&c3_lock);
acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
c3_cpu_count--;
spin_unlock(&c3_lock);
}
#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
@ -1626,12 +1617,14 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
case ACPI_STATE_C1:
state->flags |= CPUIDLE_FLAG_SHALLOW;
state->enter = acpi_idle_enter_c1;
dev->safe_state = state;
break;
case ACPI_STATE_C2:
state->flags |= CPUIDLE_FLAG_BALANCED;
state->flags |= CPUIDLE_FLAG_TIME_VALID;
state->enter = acpi_idle_enter_simple;
dev->safe_state = state;
break;
case ACPI_STATE_C3:
@ -1652,14 +1645,6 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
if (!count)
return -EINVAL;
/* find the deepest state that can handle active BM */
if (pr->flags.bm_check) {
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++)
if (pr->power.states[i].type == ACPI_STATE_C3)
break;
pr->power.bm_state = &pr->power.states[i-1];
}
return 0;
}

1
include/acpi/processor.h
View file

@ -78,7 +78,6 @@ struct acpi_processor_cx {
struct acpi_processor_power {
struct cpuidle_device dev;
struct acpi_processor_cx *state;
struct acpi_processor_cx *bm_state;
unsigned long bm_check_timestamp;
u32 default_state;
u32 bm_activity;

1
include/linux/cpuidle.h
View file

@ -92,6 +92,7 @@ struct cpuidle_device {
struct kobject kobj;
struct completion kobj_unregister;
void *governor_data;
struct cpuidle_state *safe_state;
};
DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);