diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kernel/i8253.c | 11 | ||||
| -rw-r--r-- | drivers/clocksource/i8253.c | 13 | ||||
| -rw-r--r-- | include/linux/i8253.h | 1 |
3 files changed, 19 insertions, 6 deletions
diff --git a/arch/x86/kernel/i8253.c b/arch/x86/kernel/i8253.c index 2b7999a1a50a..80e262bb627f 100644 --- a/arch/x86/kernel/i8253.c +++ b/arch/x86/kernel/i8253.c @@ -8,6 +8,7 @@ #include <linux/timex.h> #include <linux/i8253.h> +#include <asm/hypervisor.h> #include <asm/apic.h> #include <asm/hpet.h> #include <asm/time.h> @@ -39,9 +40,15 @@ static bool __init use_pit(void) bool __init pit_timer_init(void) { - if (!use_pit()) + if (!use_pit()) { + /* + * Don't just ignore the PIT. Ensure it's stopped, because + * VMMs otherwise steal CPU time just to pointlessly waggle + * the (masked) IRQ. + */ + clockevent_i8253_disable(); return false; - + } clockevent_i8253_init(true); global_clock_event = &i8253_clockevent; return true; diff --git a/drivers/clocksource/i8253.c b/drivers/clocksource/i8253.c index d4350bb10b83..cb215e6f2e83 100644 --- a/drivers/clocksource/i8253.c +++ b/drivers/clocksource/i8253.c @@ -108,11 +108,8 @@ int __init clocksource_i8253_init(void) #endif #ifdef CONFIG_CLKEVT_I8253 -static int pit_shutdown(struct clock_event_device *evt) +void clockevent_i8253_disable(void) { - if (!clockevent_state_oneshot(evt) && !clockevent_state_periodic(evt)) - return 0; - raw_spin_lock(&i8253_lock); outb_p(0x30, PIT_MODE); @@ -123,6 +120,14 @@ static int pit_shutdown(struct clock_event_device *evt) } raw_spin_unlock(&i8253_lock); +} + +static int pit_shutdown(struct clock_event_device *evt) +{ + if (!clockevent_state_oneshot(evt) && !clockevent_state_periodic(evt)) + return 0; + + clockevent_i8253_disable(); return 0; } diff --git a/include/linux/i8253.h b/include/linux/i8253.h index 8336b2f6f834..bf169cfef7f1 100644 --- a/include/linux/i8253.h +++ b/include/linux/i8253.h @@ -24,6 +24,7 @@ extern raw_spinlock_t i8253_lock; extern bool i8253_clear_counter_on_shutdown; extern struct clock_event_device i8253_clockevent; extern void clockevent_i8253_init(bool oneshot); +extern void clockevent_i8253_disable(void); extern void setup_pit_timer(void); |