[PATCH] x86: fix NMI with CPU hotplug

[linux-2.6-omap-h63xx.git] / arch / i386 / kernel / time_hpet.c

diff --git a/arch/i386/kernel/time_hpet.c b/arch/i386/kernel/time_hpet.c
index 658c0629ba6aa9e9d2062cd9111ba14a3b888e0c..9caeaa315cd7c00157ba7621a8c2082e116cfa68 100644 (file)
--- a/arch/i386/kernel/time_hpet.c
+++ b/arch/i386/kernel/time_hpet.c
@@ -275,6 +275,7 @@ static unsigned long PIE_freq = DEFAULT_RTC_INT_FREQ;
 static unsigned long PIE_count;
 
 static unsigned long hpet_rtc_int_freq; /* RTC interrupt frequency */
+static unsigned int hpet_t1_cmp; /* cached comparator register */
 
 /*
  * Timer 1 for RTC, we do not use periodic interrupt feature,
@@ -306,10 +307,12 @@ int hpet_rtc_timer_init(void)
        cnt = hpet_readl(HPET_COUNTER);
        cnt += ((hpet_tick*HZ)/hpet_rtc_int_freq);
        hpet_writel(cnt, HPET_T1_CMP);
+       hpet_t1_cmp = cnt;
        local_irq_restore(flags);
 
        cfg = hpet_readl(HPET_T1_CFG);
-       cfg |= HPET_TN_ENABLE | HPET_TN_SETVAL | HPET_TN_32BIT;
+       cfg &= ~HPET_TN_PERIODIC;
+       cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
        hpet_writel(cfg, HPET_T1_CFG);
 
        return 1;
@@ -319,8 +322,12 @@ static void hpet_rtc_timer_reinit(void)
 {
        unsigned int cfg, cnt;
 
-       if (!(PIE_on | AIE_on | UIE_on))
+       if (unlikely(!(PIE_on | AIE_on | UIE_on))) {
+               cfg = hpet_readl(HPET_T1_CFG);
+               cfg &= ~HPET_TN_ENABLE;
+               hpet_writel(cfg, HPET_T1_CFG);
                return;
+       }
 
        if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ))
                hpet_rtc_int_freq = PIE_freq;
@@ -328,15 +335,10 @@ static void hpet_rtc_timer_reinit(void)
                hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
 
        /* It is more accurate to use the comparator value than current count.*/
-       cnt = hpet_readl(HPET_T1_CMP);
+       cnt = hpet_t1_cmp;
        cnt += hpet_tick*HZ/hpet_rtc_int_freq;
        hpet_writel(cnt, HPET_T1_CMP);
-
-       cfg = hpet_readl(HPET_T1_CFG);
-       cfg |= HPET_TN_ENABLE | HPET_TN_SETVAL | HPET_TN_32BIT;
-       hpet_writel(cfg, HPET_T1_CFG);
-
-       return;
+       hpet_t1_cmp = cnt;
 }
 
 /*