[PATCH] i386: Detect clock skew during suspend
Detect the situations in which the time after a resume from disk would be earlier than the time before the suspend and prevent them from happening on i386. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: John Stultz <johnstul@us.ibm.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
parent
e1da95ae38
commit
7d145aa3ab
|
@ -270,16 +270,19 @@ void notify_arch_cmos_timer(void)
|
||||||
mod_timer(&sync_cmos_timer, jiffies + 1);
|
mod_timer(&sync_cmos_timer, jiffies + 1);
|
||||||
}
|
}
|
||||||
|
|
||||||
static long clock_cmos_diff, sleep_start;
|
static long clock_cmos_diff;
|
||||||
|
static unsigned long sleep_start;
|
||||||
|
|
||||||
static int timer_suspend(struct sys_device *dev, pm_message_t state)
|
static int timer_suspend(struct sys_device *dev, pm_message_t state)
|
||||||
{
|
{
|
||||||
/*
|
/*
|
||||||
* Estimate time zone so that set_time can update the clock
|
* Estimate time zone so that set_time can update the clock
|
||||||
*/
|
*/
|
||||||
clock_cmos_diff = -get_cmos_time();
|
unsigned long ctime = get_cmos_time();
|
||||||
|
|
||||||
|
clock_cmos_diff = -ctime;
|
||||||
clock_cmos_diff += get_seconds();
|
clock_cmos_diff += get_seconds();
|
||||||
sleep_start = get_cmos_time();
|
sleep_start = ctime;
|
||||||
return 0;
|
return 0;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
@ -287,16 +290,25 @@ static int timer_resume(struct sys_device *dev)
|
||||||
{
|
{
|
||||||
unsigned long flags;
|
unsigned long flags;
|
||||||
unsigned long sec;
|
unsigned long sec;
|
||||||
unsigned long sleep_length;
|
unsigned long ctime = get_cmos_time();
|
||||||
|
long sleep_length = (ctime - sleep_start) * HZ;
|
||||||
struct timespec ts;
|
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
|
#ifdef CONFIG_HPET_TIMER
|
||||||
if (is_hpet_enabled())
|
if (is_hpet_enabled())
|
||||||
hpet_reenable();
|
hpet_reenable();
|
||||||
#endif
|
#endif
|
||||||
setup_pit_timer();
|
setup_pit_timer();
|
||||||
sec = get_cmos_time() + clock_cmos_diff;
|
|
||||||
sleep_length = (get_cmos_time() - sleep_start) * HZ;
|
|
||||||
|
|
||||||
|
sec = ctime + clock_cmos_diff;
|
||||||
ts.tv_sec = sec;
|
ts.tv_sec = sec;
|
||||||
ts.tv_nsec = 0;
|
ts.tv_nsec = 0;
|
||||||
do_settimeofday(&ts);
|
do_settimeofday(&ts);
|
||||||
|
|
Loading…
Reference in a new issue