[PATCH] hpet-RTC: disable interrupt when no longer needed

When the emulated RTC interrupt is no longer needed, we better disable it;
otherwise, we get a spurious interrupt whenever the timer has rolled over and
reaches the same comparator value.

Having a superfluous interrupt every five minutes doesn't hurt much, but it's
bad style anyway.  ;-)

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Acked-by: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/i386/kernel/time_hpet.c b/arch/i386/kernel/time_hpet.c
index 658c0629ba6aa9e9d2062cd9111ba14a3b888e0c..23e81fcbeaea80bc19953684a15c389ab770d4d1 100644 (file)
--- a/arch/i386/kernel/time_hpet.c
+++ b/arch/i386/kernel/time_hpet.c
@@ -319,8 +319,12 @@ 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;

diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index bd5ea09bfdf9fc2d39dd153c162729574219fce9..7037ca668c63e0336a87d40d2f212513635b734f 100644 (file)
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -1138,8 +1138,12 @@ 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;