diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c index 6147770b4347..7a0a3e8d5d72 100644 --- a/arch/x86_64/kernel/apic.c +++ b/arch/x86_64/kernel/apic.c @@ -708,7 +708,7 @@ static void setup_APIC_timer(unsigned int clocks) local_irq_save(flags); /* wait for irq slice */ - if (vxtime.hpet_address) { + if (vxtime.hpet_address && hpet_use_timer) { int trigger = hpet_readl(HPET_T0_CMP); while (hpet_readl(HPET_COUNTER) >= trigger) /* do nothing */ ; diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c index dba7237be5c1..3c58c30506a1 100644 --- a/arch/x86_64/kernel/time.c +++ b/arch/x86_64/kernel/time.c @@ -59,7 +59,7 @@ static int notsc __initdata = 0; unsigned int cpu_khz; /* TSC clocks / usec, not used here */ static unsigned long hpet_period; /* fsecs / HPET clock */ unsigned long hpet_tick; /* HPET clocks / interrupt */ -static int hpet_use_timer; /* Use counter of hpet for time keeping, otherwise PIT */ +int hpet_use_timer; /* Use counter of hpet for time keeping, otherwise PIT */ unsigned long vxtime_hz = PIT_TICK_RATE; int report_lost_ticks; /* command line option */ unsigned long long monotonic_base; @@ -326,7 +326,10 @@ static noinline void handle_lost_ticks(int lost, struct pt_regs *regs) print_symbol("rip %s\n", regs->rip); if (vxtime.mode == VXTIME_TSC && vxtime.hpet_address) { printk(KERN_WARNING "Falling back to HPET\n"); - vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick; + if (hpet_use_timer) + vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick; + else + vxtime.last = hpet_readl(HPET_COUNTER); vxtime.mode = VXTIME_HPET; do_gettimeoffset = do_gettimeoffset_hpet; } @@ -988,7 +991,10 @@ void __init time_init_gtod(void) notsc = 1; if (vxtime.hpet_address && notsc) { timetype = hpet_use_timer ? "HPET" : "PIT/HPET"; - vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick; + if (hpet_use_timer) + vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick; + else + vxtime.last = hpet_readl(HPET_COUNTER); vxtime.mode = VXTIME_HPET; do_gettimeoffset = do_gettimeoffset_hpet; #ifdef CONFIG_X86_PM_TIMER diff --git a/include/asm-x86_64/hpet.h b/include/asm-x86_64/hpet.h index c20c28f5c7a0..08b75c15269a 100644 --- a/include/asm-x86_64/hpet.h +++ b/include/asm-x86_64/hpet.h @@ -55,6 +55,8 @@ extern int is_hpet_enabled(void); extern int hpet_rtc_timer_init(void); extern int oem_force_hpet_timer(void); +extern int hpet_use_timer; + #ifdef CONFIG_HPET_EMULATE_RTC extern int hpet_mask_rtc_irq_bit(unsigned long bit_mask); extern int hpet_set_rtc_irq_bit(unsigned long bit_mask);