diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c index 2eeaa95edff0..7392570f975d 100644 --- a/arch/x86_64/kernel/time.c +++ b/arch/x86_64/kernel/time.c @@ -917,6 +917,8 @@ void __init time_init(void) vxtime.hpet_address = 0; if (hpet_use_timer) { + /* set tick_nsec to use the proper rate for HPET */ + tick_nsec = TICK_NSEC_HPET; cpu_khz = hpet_calibrate_tsc(); timename = "HPET"; #ifdef CONFIG_X86_PM_TIMER diff --git a/include/asm-i386/hpet.h b/include/asm-i386/hpet.h index 16ef9f996e3f..7f1a8a6ee32f 100644 --- a/include/asm-i386/hpet.h +++ b/include/asm-i386/hpet.h @@ -89,6 +89,7 @@ * then 32 bit HPET counter wrapsaround in less than 0.5 sec. */ #define HPET_MIN_PERIOD (100000UL) +#define HPET_TICK_RATE (HZ * 100000UL) extern unsigned long hpet_tick; /* hpet clks count per tick */ extern unsigned long hpet_address; /* hpet memory map physical address */ diff --git a/include/asm-x86_64/hpet.h b/include/asm-x86_64/hpet.h index 08b75c15269a..18ff7ee9e774 100644 --- a/include/asm-x86_64/hpet.h +++ b/include/asm-x86_64/hpet.h @@ -51,6 +51,8 @@ #define HPET_TN_ROUTE_SHIFT 9 +#define HPET_TICK_RATE (HZ * 100000UL) + extern int is_hpet_enabled(void); extern int hpet_rtc_timer_init(void); extern int oem_force_hpet_timer(void); diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h index 99905e180532..043376920f51 100644 --- a/include/linux/jiffies.h +++ b/include/linux/jiffies.h @@ -36,6 +36,8 @@ /* LATCH is used in the interval timer and ftape setup. */ #define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */ +#define LATCH_HPET ((HPET_TICK_RATE + HZ/2) / HZ) + /* Suppose we want to devide two numbers NOM and DEN: NOM/DEN, the we can * improve accuracy by shifting LSH bits, hence calculating: * (NOM << LSH) / DEN @@ -51,9 +53,13 @@ /* HZ is the requested value. ACTHZ is actual HZ ("<< 8" is for accuracy) */ #define ACTHZ (SH_DIV (CLOCK_TICK_RATE, LATCH, 8)) +#define ACTHZ_HPET (SH_DIV (HPET_TICK_RATE, LATCH_HPET, 8)) + /* TICK_NSEC is the time between ticks in nsec assuming real ACTHZ */ #define TICK_NSEC (SH_DIV (1000000UL * 1000, ACTHZ, 8)) +#define TICK_NSEC_HPET (SH_DIV(1000000UL * 1000, ACTHZ_HPET, 8)) + /* TICK_USEC is the time between ticks in usec assuming fake USER_HZ */ #define TICK_USEC ((1000000UL + USER_HZ/2) / USER_HZ) diff --git a/kernel/timer.c b/kernel/timer.c index c3a874f1393c..471ab8710b8f 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1455,7 +1455,7 @@ static void time_interpolator_update(long delta_nsec) */ if (jiffies % INTERPOLATOR_ADJUST == 0) { - if (time_interpolator->skips == 0 && time_interpolator->offset > TICK_NSEC) + if (time_interpolator->skips == 0 && time_interpolator->offset > tick_nsec) time_interpolator->nsec_per_cyc--; if (time_interpolator->ns_skipped > INTERPOLATOR_MAX_SKIP && time_interpolator->offset == 0) time_interpolator->nsec_per_cyc++;