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-rw-r--r--arch/i386/kernel/time.c2
-rw-r--r--arch/i386/kernel/time_hpet.c48
-rw-r--r--arch/i386/kernel/timers/timer_hpet.c11
-rw-r--r--arch/i386/kernel/timers/timer_tsc.c2
-rw-r--r--include/asm-i386/hpet.h1
5 files changed, 37 insertions, 27 deletions
diff --git a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c
index 4d75b373f90..a0dcb7c87c3 100644
--- a/arch/i386/kernel/time.c
+++ b/arch/i386/kernel/time.c
@@ -441,7 +441,7 @@ static void __init hpet_time_init(void)
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
- if (hpet_enable() >= 0) {
+ if ((hpet_enable() >= 0) && hpet_use_timer) {
printk("Using HPET for base-timer\n");
}
diff --git a/arch/i386/kernel/time_hpet.c b/arch/i386/kernel/time_hpet.c
index 244a31b04be..10a0cbb88e7 100644
--- a/arch/i386/kernel/time_hpet.c
+++ b/arch/i386/kernel/time_hpet.c
@@ -26,6 +26,7 @@
static unsigned long hpet_period; /* fsecs / HPET clock */
unsigned long hpet_tick; /* hpet clks count per tick */
unsigned long hpet_address; /* hpet memory map physical address */
+int hpet_use_timer;
static int use_hpet; /* can be used for runtime check of hpet */
static int boot_hpet_disable; /* boottime override for HPET timer */
@@ -73,27 +74,30 @@ static int hpet_timer_stop_set_go(unsigned long tick)
hpet_writel(0, HPET_COUNTER);
hpet_writel(0, HPET_COUNTER + 4);
- /*
- * Set up timer 0, as periodic with first interrupt to happen at
- * hpet_tick, and period also hpet_tick.
- */
- cfg = hpet_readl(HPET_T0_CFG);
- cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
- HPET_TN_SETVAL | HPET_TN_32BIT;
- hpet_writel(cfg, HPET_T0_CFG);
-
- /*
- * The first write after writing TN_SETVAL to the config register sets
- * the counter value, the second write sets the threshold.
- */
- hpet_writel(tick, HPET_T0_CMP);
- hpet_writel(tick, HPET_T0_CMP);
+ if (hpet_use_timer) {
+ /*
+ * Set up timer 0, as periodic with first interrupt to happen at
+ * hpet_tick, and period also hpet_tick.
+ */
+ cfg = hpet_readl(HPET_T0_CFG);
+ cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
+ HPET_TN_SETVAL | HPET_TN_32BIT;
+ hpet_writel(cfg, HPET_T0_CFG);
+ /*
+ * The first write after writing TN_SETVAL to the config register sets
+ * the counter value, the second write sets the threshold.
+ */
+ hpet_writel(tick, HPET_T0_CMP);
+ hpet_writel(tick, HPET_T0_CMP);
+ }
/*
* Go!
*/
cfg = hpet_readl(HPET_CFG);
- cfg |= HPET_CFG_ENABLE | HPET_CFG_LEGACY;
+ if (hpet_use_timer)
+ cfg |= HPET_CFG_LEGACY;
+ cfg |= HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
return 0;
@@ -128,12 +132,11 @@ int __init hpet_enable(void)
* However, we can do with one timer otherwise using the
* the single HPET timer for system time.
*/
- if (
#ifdef CONFIG_HPET_EMULATE_RTC
- !(id & HPET_ID_NUMBER) ||
-#endif
- !(id & HPET_ID_LEGSUP))
+ if (!(id & HPET_ID_NUMBER))
return -1;
+#endif
+
hpet_period = hpet_readl(HPET_PERIOD);
if ((hpet_period < HPET_MIN_PERIOD) || (hpet_period > HPET_MAX_PERIOD))
@@ -152,6 +155,8 @@ int __init hpet_enable(void)
if (hpet_tick_rem > (hpet_period >> 1))
hpet_tick++; /* rounding the result */
+ hpet_use_timer = id & HPET_ID_LEGSUP;
+
if (hpet_timer_stop_set_go(hpet_tick))
return -1;
@@ -202,7 +207,8 @@ int __init hpet_enable(void)
#endif
#ifdef CONFIG_X86_LOCAL_APIC
- wait_timer_tick = wait_hpet_tick;
+ if (hpet_use_timer)
+ wait_timer_tick = wait_hpet_tick;
#endif
return 0;
}
diff --git a/arch/i386/kernel/timers/timer_hpet.c b/arch/i386/kernel/timers/timer_hpet.c
index 713134e7184..f778f471a09 100644
--- a/arch/i386/kernel/timers/timer_hpet.c
+++ b/arch/i386/kernel/timers/timer_hpet.c
@@ -79,7 +79,7 @@ static unsigned long get_offset_hpet(void)
eax = hpet_readl(HPET_COUNTER);
eax -= hpet_last; /* hpet delta */
-
+ eax = min(hpet_tick, eax);
/*
* Time offset = (hpet delta) * ( usecs per HPET clock )
* = (hpet delta) * ( usecs per tick / HPET clocks per tick)
@@ -105,9 +105,12 @@ static void mark_offset_hpet(void)
last_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
rdtsc(last_tsc_low, last_tsc_high);
- offset = hpet_readl(HPET_T0_CMP) - hpet_tick;
- if (unlikely(((offset - hpet_last) > hpet_tick) && (hpet_last != 0))) {
- int lost_ticks = (offset - hpet_last) / hpet_tick;
+ if (hpet_use_timer)
+ offset = hpet_readl(HPET_T0_CMP) - hpet_tick;
+ else
+ offset = hpet_readl(HPET_COUNTER);
+ if (unlikely(((offset - hpet_last) >= (2*hpet_tick)) && (hpet_last != 0))) {
+ int lost_ticks = ((offset - hpet_last) / hpet_tick) - 1;
jiffies_64 += lost_ticks;
}
hpet_last = offset;
diff --git a/arch/i386/kernel/timers/timer_tsc.c b/arch/i386/kernel/timers/timer_tsc.c
index a685994e5c8..7926d967be0 100644
--- a/arch/i386/kernel/timers/timer_tsc.c
+++ b/arch/i386/kernel/timers/timer_tsc.c
@@ -477,7 +477,7 @@ static int __init init_tsc(char* override)
if (cpu_has_tsc) {
unsigned long tsc_quotient;
#ifdef CONFIG_HPET_TIMER
- if (is_hpet_enabled()){
+ if (is_hpet_enabled() && hpet_use_timer) {
unsigned long result, remain;
printk("Using TSC for gettimeofday\n");
tsc_quotient = calibrate_tsc_hpet(NULL);
diff --git a/include/asm-i386/hpet.h b/include/asm-i386/hpet.h
index 6e20b079f1d..16ef9f996e3 100644
--- a/include/asm-i386/hpet.h
+++ b/include/asm-i386/hpet.h
@@ -92,6 +92,7 @@
extern unsigned long hpet_tick; /* hpet clks count per tick */
extern unsigned long hpet_address; /* hpet memory map physical address */
+extern int hpet_use_timer;
extern int hpet_rtc_timer_init(void);
extern int hpet_enable(void);