1 files changed, 17 insertions, 4 deletions

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index d592dbb1d12..283c08f5f4d 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -272,6 +272,8 @@ static atomic_t c3_cpu_count;
 /* Common C-state entry for C2, C3, .. */
 static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
 {
+        /* Don't trace irqs off for idle */
+        stop_critical_timings();
         if (cstate->entry_method == ACPI_CSTATE_FFH) {
                 /* Call into architectural FFH based C-state */
                 acpi_processor_ffh_cstate_enter(cstate);
@@ -284,6 +286,7 @@ static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
                    gets asserted in time to freeze execution properly. */
                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
         }
+        start_critical_timings();
 }
 #endif /* !CONFIG_CPU_IDLE */
 
@@ -1329,9 +1332,15 @@ int acpi_processor_cst_has_changed(struct acpi_processor *pr)
         if (!pr->flags.power_setup_done)
                 return -ENODEV;
 
-        /* Fall back to the default idle loop */
-        pm_idle = pm_idle_save;
-        synchronize_sched();    /* Relies on interrupts forcing exit from idle. */
+        /*
+         * Fall back to the default idle loop, when pm_idle_save had
+         * been initialized.
+         */
+        if (pm_idle_save) {
+                pm_idle = pm_idle_save;
+                /* Relies on interrupts forcing exit from idle. */
+                synchronize_sched();
+        }
 
         pr->flags.power = 0;
         result = acpi_processor_get_power_info(pr);
@@ -1418,6 +1427,8 @@ static inline void acpi_idle_update_bm_rld(struct acpi_processor *pr,
  */
 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 {
+        /* Don't trace irqs off for idle */
+        stop_critical_timings();
         if (cx->entry_method == ACPI_CSTATE_FFH) {
                 /* Call into architectural FFH based C-state */
                 acpi_processor_ffh_cstate_enter(cx);
@@ -1432,6 +1443,7 @@ static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
                    gets asserted in time to freeze execution properly. */
                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
         }
+        start_critical_timings();
 }
 
 /**
@@ -1890,7 +1902,8 @@ int acpi_processor_power_exit(struct acpi_processor *pr,
 
         /* Unregister the idle handler when processor #0 is removed. */
         if (pr->id == 0) {
-                pm_idle = pm_idle_save;
+                if (pm_idle_save)
+                        pm_idle = pm_idle_save;
 
                 /*
                  * We are about to unload the current idle thread pm callback