Commit c3c433e4 authored by Shaohua Li's avatar Shaohua Li Committed by Linus Torvalds
Browse files

[PATCH] add suspend/resume for timer 



The timers lack .suspend/.resume methods.  Because of this, jiffies got a
big compensation after a S3 resume.  And then softlockup watchdog reports
an oops.  This occured with HPET enabled, but it's also possible for other
timers.

Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 57c4ce3c

arch/i386/kernel/time.c

+10 −0
Original line number Diff line number Diff line
@@ -383,6 +383,7 @@ void notify_arch_cmos_timer(void) 


static long clock_cmos_diff, sleep_start;



static struct timer_opts *last_timer;

static int timer_suspend(struct sys_device *dev, pm_message_t state)

{

	/*
@@ -391,6 +392,10 @@ static int timer_suspend(struct sys_device *dev, pm_message_t state) 
	clock_cmos_diff = -get_cmos_time();

	clock_cmos_diff += get_seconds();

	sleep_start = get_cmos_time();

	last_timer = cur_timer;

	cur_timer = &timer_none;

	if (last_timer->suspend)

		last_timer->suspend(state);

	return 0;

}
@@ -404,6 +409,7 @@ static int timer_resume(struct sys_device *dev) 
	if (is_hpet_enabled())

		hpet_reenable();

#endif

	setup_pit_timer();

	sec = get_cmos_time() + clock_cmos_diff;

	sleep_length = (get_cmos_time() - sleep_start) * HZ;

	write_seqlock_irqsave(&xtime_lock, flags);
@@ -412,6 +418,10 @@ static int timer_resume(struct sys_device *dev) 
	write_sequnlock_irqrestore(&xtime_lock, flags);

	jiffies += sleep_length;

	wall_jiffies += sleep_length;

	if (last_timer->resume)

		last_timer->resume();

	cur_timer = last_timer;

	last_timer = NULL;

	return 0;

}

arch/i386/kernel/timers/timer_hpet.c

+14 −0
Original line number Diff line number Diff line
@@ -181,6 +181,19 @@ static int __init init_hpet(char* override) 
	return 0;

}



static int hpet_resume(void)

{

	write_seqlock(&monotonic_lock);

	/* Assume this is the last mark offset time */

	rdtsc(last_tsc_low, last_tsc_high);



	if (hpet_use_timer)

		hpet_last = hpet_readl(HPET_T0_CMP) - hpet_tick;

	else

		hpet_last = hpet_readl(HPET_COUNTER);

	write_sequnlock(&monotonic_lock);

	return 0;

}

/************************************************************/



/* tsc timer_opts struct */
@@ -190,6 +203,7 @@ static struct timer_opts timer_hpet __read_mostly = { 
	.get_offset =		get_offset_hpet,

	.monotonic_clock =	monotonic_clock_hpet,

	.delay = 		delay_hpet,

	.resume	=		hpet_resume,

};



struct init_timer_opts __initdata timer_hpet_init = {

arch/i386/kernel/timers/timer_pit.c

+0 −27
Original line number Diff line number Diff line
@@ -175,30 +175,3 @@ void setup_pit_timer(void) 
	outb(LATCH >> 8 , PIT_CH0);	/* MSB */

	spin_unlock_irqrestore(&i8253_lock, flags);

}
 


static int timer_resume(struct sys_device *dev)

{

	setup_pit_timer();

	return 0;

}



static struct sysdev_class timer_sysclass = {

	set_kset_name("timer_pit"),

	.resume	= timer_resume,

};



static struct sys_device device_timer = {

	.id	= 0,

	.cls	= &timer_sysclass,

};



static int __init init_timer_sysfs(void)

{

	int error = sysdev_class_register(&timer_sysclass);

	if (!error)

		error = sysdev_register(&device_timer);

	return error;

}



device_initcall(init_timer_sysfs);

arch/i386/kernel/timers/timer_pm.c

+9 −0
Original line number Diff line number Diff line
@@ -186,6 +186,14 @@ static void mark_offset_pmtmr(void) 
	}

}



static int pmtmr_resume(void)

{

	write_seqlock(&monotonic_lock);

	/* Assume this is the last mark offset time */

	offset_tick = read_pmtmr();

	write_sequnlock(&monotonic_lock);

	return 0;

}



static unsigned long long monotonic_clock_pmtmr(void)

{
@@ -247,6 +255,7 @@ static struct timer_opts timer_pmtmr = { 
	.monotonic_clock 	= monotonic_clock_pmtmr,

	.delay 			= delay_pmtmr,

	.read_timer 		= read_timer_tsc,

	.resume			= pmtmr_resume,

};



struct init_timer_opts __initdata timer_pmtmr_init = {

arch/i386/kernel/timers/timer_tsc.c

+14 −0
Original line number Diff line number Diff line
@@ -543,6 +543,19 @@ static int __init init_tsc(char* override) 
	return -ENODEV;

}



static int tsc_resume(void)

{

	write_seqlock(&monotonic_lock);

	/* Assume this is the last mark offset time */

	rdtsc(last_tsc_low, last_tsc_high);

#ifdef CONFIG_HPET_TIMER

	if (is_hpet_enabled() && hpet_use_timer)

		hpet_last = hpet_readl(HPET_COUNTER);

#endif

	write_sequnlock(&monotonic_lock);

	return 0;

}



#ifndef CONFIG_X86_TSC

/* disable flag for tsc.  Takes effect by clearing the TSC cpu flag

 * in cpu/common.c */
@@ -573,6 +586,7 @@ static struct timer_opts timer_tsc = { 
	.monotonic_clock = monotonic_clock_tsc,

	.delay = delay_tsc,

	.read_timer = read_timer_tsc,

	.resume	= tsc_resume,

};



struct init_timer_opts __initdata timer_tsc_init = {

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