From: John Stultz persistent clock support: do proper timekeeping across suspend/resume, i386 arch support. Signed-off-by: John Stultz Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar -- arch/i386/kernel/apm.c | 44 --------------------------------------- arch/i386/kernel/time.c | 54 +----------------------------------------------- 2 files changed, 2 insertions(+), 96 deletions(-) linux-2.6.18-rc6_timeofday-persistent-clock-i386_C6.patch Index: linux-2.6.18-mm2/arch/i386/kernel/apm.c =================================================================== --- linux-2.6.18-mm2.orig/arch/i386/kernel/apm.c 2006-10-02 00:55:49.000000000 +0200 +++ linux-2.6.18-mm2/arch/i386/kernel/apm.c 2006-10-02 00:55:50.000000000 +0200 @@ -234,7 +234,6 @@ #include "io_ports.h" -extern unsigned long get_cmos_time(void); extern void machine_real_restart(unsigned char *, int); #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT) @@ -1153,28 +1152,6 @@ out: spin_unlock(&user_list_lock); } -static void set_time(void) -{ - struct timespec ts; - if (got_clock_diff) { /* Must know time zone in order to set clock */ - ts.tv_sec = get_cmos_time() + clock_cmos_diff; - ts.tv_nsec = 0; - do_settimeofday(&ts); - } -} - -static void get_time_diff(void) -{ -#ifndef CONFIG_APM_RTC_IS_GMT - /* - * Estimate time zone so that set_time can update the clock - */ - clock_cmos_diff = -get_cmos_time(); - clock_cmos_diff += get_seconds(); - got_clock_diff = 1; -#endif -} - static void reinit_timer(void) { #ifdef INIT_TIMER_AFTER_SUSPEND @@ -1214,19 +1191,6 @@ static int suspend(int vetoable) local_irq_disable(); device_power_down(PMSG_SUSPEND); - /* serialize with the timer interrupt */ - write_seqlock(&xtime_lock); - - /* protect against access to timer chip registers */ - spin_lock(&i8253_lock); - - get_time_diff(); - /* - * Irq spinlock must be dropped around set_system_power_state. - * We'll undo any timer changes due to interrupts below. - */ - spin_unlock(&i8253_lock); - write_sequnlock(&xtime_lock); local_irq_enable(); save_processor_state(); @@ -1235,7 +1199,6 @@ static int suspend(int vetoable) restore_processor_state(); local_irq_disable(); - set_time(); reinit_timer(); if (err == APM_NO_ERROR) @@ -1265,11 +1228,6 @@ static void standby(void) local_irq_disable(); device_power_down(PMSG_SUSPEND); - /* serialize with the timer interrupt */ - write_seqlock(&xtime_lock); - /* If needed, notify drivers here */ - get_time_diff(); - write_sequnlock(&xtime_lock); local_irq_enable(); err = set_system_power_state(APM_STATE_STANDBY); @@ -1363,7 +1321,6 @@ static void check_events(void) ignore_bounce = 1; if ((event != APM_NORMAL_RESUME) || (ignore_normal_resume == 0)) { - set_time(); device_resume(); pm_send_all(PM_RESUME, (void *)0); queue_event(event, NULL); @@ -1379,7 +1336,6 @@ static void check_events(void) break; case APM_UPDATE_TIME: - set_time(); break; case APM_CRITICAL_SUSPEND: Index: linux-2.6.18-mm2/arch/i386/kernel/time.c =================================================================== --- linux-2.6.18-mm2.orig/arch/i386/kernel/time.c 2006-10-02 00:55:49.000000000 +0200 +++ linux-2.6.18-mm2/arch/i386/kernel/time.c 2006-10-02 00:55:50.000000000 +0200 @@ -216,7 +216,7 @@ irqreturn_t timer_interrupt(int irq, voi } /* not static: needed by APM */ -unsigned long get_cmos_time(void) +unsigned long read_persistent_clock(void) { unsigned long retval; unsigned long flags; @@ -232,7 +232,7 @@ unsigned long get_cmos_time(void) return retval; } -EXPORT_SYMBOL(get_cmos_time); +EXPORT_SYMBOL(read_persistent_clock); static void sync_cmos_clock(unsigned long dummy); @@ -283,58 +283,19 @@ void notify_arch_cmos_timer(void) mod_timer(&sync_cmos_timer, jiffies + 1); } -static long clock_cmos_diff; -static unsigned long sleep_start; - -static int timer_suspend(struct sys_device *dev, pm_message_t state) -{ - /* - * Estimate time zone so that set_time can update the clock - */ - unsigned long ctime = get_cmos_time(); - - clock_cmos_diff = -ctime; - clock_cmos_diff += get_seconds(); - sleep_start = ctime; - return 0; -} - static int timer_resume(struct sys_device *dev) { - unsigned long flags; - unsigned long sec; - unsigned long ctime = get_cmos_time(); - long sleep_length = (ctime - sleep_start) * HZ; - struct timespec ts; - - if (sleep_length < 0) { - printk(KERN_WARNING "CMOS clock skew detected in timer resume!\n"); - /* The time after the resume must not be earlier than the time - * before the suspend or some nasty things will happen - */ - sleep_length = 0; - ctime = sleep_start; - } #ifdef CONFIG_HPET_TIMER if (is_hpet_enabled()) hpet_reenable(); #endif setup_pit_timer(); - sec = ctime + clock_cmos_diff; - ts.tv_sec = sec; - ts.tv_nsec = 0; - do_settimeofday(&ts); - write_seqlock_irqsave(&xtime_lock, flags); - jiffies_64 += sleep_length; - write_sequnlock_irqrestore(&xtime_lock, flags); - touch_softlockup_watchdog(); return 0; } static struct sysdev_class timer_sysclass = { .resume = timer_resume, - .suspend = timer_suspend, set_kset_name("timer"), }; @@ -360,12 +321,6 @@ extern void (*late_time_init)(void); /* Duplicate of time_init() below, with hpet_enable part added */ static void __init hpet_time_init(void) { - struct timespec ts; - ts.tv_sec = get_cmos_time(); - ts.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ); - - do_settimeofday(&ts); - if ((hpet_enable() >= 0) && hpet_use_timer) { printk("Using HPET for base-timer\n"); } @@ -376,7 +331,6 @@ static void __init hpet_time_init(void) void __init time_init(void) { - struct timespec ts; #ifdef CONFIG_HPET_TIMER if (is_hpet_capable()) { /* @@ -387,10 +341,6 @@ void __init time_init(void) return; } #endif - ts.tv_sec = get_cmos_time(); - ts.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ); - - do_settimeofday(&ts); time_init_hook(); } -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/