[PATCH] hpet-RTC: cache the comparator register

[pandora-kernel.git] / arch / x86_64 / kernel / time.c

diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index 35a896e..fdaddc4 100644 (file)
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -1089,6 +1089,7 @@ 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 */
 
 int is_hpet_enabled(void)
 {
@@ -1125,6 +1126,7 @@ 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);
@@ -1152,9 +1154,10 @@ 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);
+       hpet_t1_cmp = cnt;
 }
 
 /*