[PATCH] hpet-RTC: fix timer config register accesses

Make sure that the RTC timer is in non-periodic mode; some stupid BIOS might
have initialized it to periodic mode.

Furthermore, don't set the SETVAL bit in the config register.  This wouldn't
have any effect unless the timer was in period mode (which it isn't), and then
the actual timer frequency would be half that of the desired one because
incrementing the comparator in the interrupt handler would be done after the
hardware has already incremented it itself.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
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 23e81fcbeaea80bc19953684a15c389ab770d4d1..cb1f313858e300d593853c64f72db2770d25eac2 100644 (file)
--- a/arch/i386/kernel/time_hpet.c
+++ b/arch/i386/kernel/time_hpet.c
@@ -309,7 +309,8 @@ int hpet_rtc_timer_init(void)
        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;
@@ -335,12 +336,6 @@ static void hpet_rtc_timer_reinit(void)
        cnt = hpet_readl(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;
 }
 
 /*

diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index 7037ca668c63e0336a87d40d2f212513635b734f..35a896ef4c352671caec6878c7d980761015b761 100644 (file)
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -1128,7 +1128,8 @@ int hpet_rtc_timer_init(void)
        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;
@@ -1154,12 +1155,6 @@ static void hpet_rtc_timer_reinit(void)
        cnt = hpet_readl(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;
 }
 
 /*