1 files changed, 11 insertions, 11 deletions

diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
index 62122134693b..d269a8f3329c 100644
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -43,6 +43,10 @@ static DEFINE_MUTEX(isolated_cpus_lock);
 #define CPUID5_ECX_EXTENSIONS_SUPPORTED (0x1)
 #define CPUID5_ECX_INTERRUPT_BREAK      (0x2)
 static unsigned long power_saving_mwait_eax;
+
+static unsigned char tsc_detected_unstable;
+static unsigned char tsc_marked_unstable;
+
 static void power_saving_mwait_init(void)
 {
         unsigned int eax, ebx, ecx, edx;
@@ -87,8 +91,8 @@ static void power_saving_mwait_init(void)
 
                 /*FALL THROUGH*/
         default:
-                /* TSC could halt in idle, so notify users */
-                mark_tsc_unstable("TSC halts in idle");
+                /* TSC could halt in idle */
+                tsc_detected_unstable = 1;
         }
 #endif
 }
@@ -168,16 +172,14 @@ static int power_saving_thread(void *data)
 
                 do_sleep = 0;
 
-                current_thread_info()->status &= ~TS_POLLING;
-                /*
-                 * TS_POLLING-cleared state must be visible before we test
-                 * NEED_RESCHED:
-                 */
-                smp_mb();
-
                 expire_time = jiffies + HZ * (100 - idle_pct) / 100;
 
                 while (!need_resched()) {
+                        if (tsc_detected_unstable && !tsc_marked_unstable) {
+                                /* TSC could halt in idle, so notify users */
+                                mark_tsc_unstable("TSC halts in idle");
+                                tsc_marked_unstable = 1;
+                        }
                         local_irq_disable();
                         cpu = smp_processor_id();
                         clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
@@ -200,8 +202,6 @@ static int power_saving_thread(void *data)
                         }
                 }
 
-                current_thread_info()->status |= TS_POLLING;
-
                 /*
                  * current sched_rt has threshold for rt task running time.
                  * When a rt task uses 95% CPU time, the rt thread will be