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authorvenkatesh.pallipadi@intel.com <venkatesh.pallipadi@intel.com>2008-01-31 17:35:03 -0800
committerLen Brown <len.brown@intel.com>2008-02-07 02:11:14 -0500
commit2e906655baf1c6f6fccd212fc9e6499dc6928b80 (patch)
treec9d3d71db721f725e6333228efaba4443e878e70 /drivers/acpi/processor_idle.c
parent488b5ec871191359b9b79262a3d48456dae7ea5f (diff)
downloadlinux-next-2e906655baf1c6f6fccd212fc9e6499dc6928b80.tar.gz
ACPI: idle: Fix acpi_safe_halt usages and interrupt enabling/disabling
acpi_safe_halt() needs interrupts to be disabled for atomic need_resched check and safe halt. Otherwise we may miss an interrupt and go into halt. acpi_safe_halt() also does not enable interrupts on all return paths. So the callers should handle enable and disable interrupts around it. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/processor_idle.c')
-rw-r--r--drivers/acpi/processor_idle.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 199ea2146153..106a22948aa9 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -201,6 +201,10 @@ static inline u32 ticks_elapsed_in_us(u32 t1, u32 t2)
return PM_TIMER_TICKS_TO_US((0xFFFFFFFF - t1) + t2);
}
+/*
+ * Callers should disable interrupts before the call and enable
+ * interrupts after return.
+ */
static void acpi_safe_halt(void)
{
current_thread_info()->status &= ~TS_POLLING;
@@ -413,6 +417,8 @@ static void acpi_processor_idle(void)
pm_idle_save();
else
acpi_safe_halt();
+
+ local_irq_enable();
return;
}
@@ -521,6 +527,7 @@ static void acpi_processor_idle(void)
* skew otherwise.
*/
sleep_ticks = 0xFFFFFFFF;
+ local_irq_enable();
break;
case ACPI_STATE_C2:
@@ -1403,11 +1410,13 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev,
if (unlikely(!pr))
return 0;
+ local_irq_disable();
if (pr->flags.bm_check)
acpi_idle_update_bm_rld(pr, cx);
acpi_safe_halt();
+ local_irq_enable();
cx->usage++;
return 0;
@@ -1517,7 +1526,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
if (dev->safe_state) {
return dev->safe_state->enter(dev, dev->safe_state);
} else {
+ local_irq_disable();
acpi_safe_halt();
+ local_irq_enable();
return 0;
}
}