1 files changed, 12 insertions, 2 deletions

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 64d5ad0b8add..a00545fe5cdd 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -269,6 +269,8 @@ static void hpet_set_mode(enum clock_event_mode mode,
                 now = hpet_readl(HPET_COUNTER);
                 cmp = now + (unsigned long) delta;
                 cfg = hpet_readl(HPET_Tn_CFG(timer));
+                /* Make sure we use edge triggered interrupts */
+                cfg &= ~HPET_TN_LEVEL;
                 cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
                        HPET_TN_SETVAL | HPET_TN_32BIT;
                 hpet_writel(cfg, HPET_Tn_CFG(timer));
@@ -897,7 +899,7 @@ static unsigned long hpet_rtc_flags;
 static int hpet_prev_update_sec;
 static struct rtc_time hpet_alarm_time;
 static unsigned long hpet_pie_count;
-static unsigned long hpet_t1_cmp;
+static u32 hpet_t1_cmp;
 static unsigned long hpet_default_delta;
 static unsigned long hpet_pie_delta;
 static unsigned long hpet_pie_limit;
@@ -905,6 +907,14 @@ static unsigned long hpet_pie_limit;
 static rtc_irq_handler irq_handler;
 
 /*
+ * Check that the hpet counter c1 is ahead of the c2
+ */
+static inline int hpet_cnt_ahead(u32 c1, u32 c2)
+{
+        return (s32)(c2 - c1) < 0;
+}
+
+/*
  * Registers a IRQ handler.
  */
 int hpet_register_irq_handler(rtc_irq_handler handler)
@@ -1075,7 +1085,7 @@ static void hpet_rtc_timer_reinit(void)
                 hpet_t1_cmp += delta;
                 hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
                 lost_ints++;
-        } while ((long)(hpet_readl(HPET_COUNTER) - hpet_t1_cmp) > 0);
+        } while (!hpet_cnt_ahead(hpet_t1_cmp, hpet_readl(HPET_COUNTER)));
 
         if (lost_ints) {
                 if (hpet_rtc_flags & RTC_PIE)