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[SPARC64]: Synchronize RTC clock via timer just like x86. 

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2007-02-22 04:16:21 -08:00
parent de46c33745
commit a58c9f3c1e
1 changed files with 48 additions and 18 deletions
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66
arch/sparc64/kernel/time.c
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@ -435,22 +435,56 @@ static unsigned long timer_ticks_per_nsec_quotient __read_mostly;
#define TICK_SIZE (tick_nsec / 1000)
static inline void timer_check_rtc(void)
{
/* last time the cmos clock got updated */
static long last_rtc_update;
#define USEC_AFTER 500000
#define USEC_BEFORE 500000
/* Determine when to update the Mostek clock. */
if (ntp_synced() &&
xtime.tv_sec > last_rtc_update + 660 &&
(xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
(xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
if (set_rtc_mmss(xtime.tv_sec) == 0)
last_rtc_update = xtime.tv_sec;
else
last_rtc_update = xtime.tv_sec - 600;
/* do it again in 60 s */
static void sync_cmos_clock(unsigned long dummy);
static DEFINE_TIMER(sync_cmos_timer, sync_cmos_clock, 0, 0);
static void sync_cmos_clock(unsigned long dummy)
{
struct timeval now, next;
int fail = 1;
/*
* If we have an externally synchronized Linux clock, then update
* CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
* called as close as possible to 500 ms before the new second starts.
* This code is run on a timer. If the clock is set, that timer
* may not expire at the correct time. Thus, we adjust...
*/
if (!ntp_synced())
/*
* Not synced, exit, do not restart a timer (if one is
* running, let it run out).
*/
return;
do_gettimeofday(&now);
if (now.tv_usec >= USEC_AFTER - ((unsigned) TICK_SIZE) / 2 &&
now.tv_usec <= USEC_BEFORE + ((unsigned) TICK_SIZE) / 2)
fail = set_rtc_mmss(now.tv_sec);
next.tv_usec = USEC_AFTER - now.tv_usec;
if (next.tv_usec <= 0)
next.tv_usec += USEC_PER_SEC;
if (!fail)
next.tv_sec = 659;
else
next.tv_sec = 0;
if (next.tv_usec >= USEC_PER_SEC) {
next.tv_sec++;
next.tv_usec -= USEC_PER_SEC;
}
mod_timer(&sync_cmos_timer, jiffies + timeval_to_jiffies(&next));
}
void notify_arch_cmos_timer(void)
{
mod_timer(&sync_cmos_timer, jiffies + 1);
}
irqreturn_t timer_interrupt(int irq, void *dev_id)
@ -483,8 +517,6 @@ irqreturn_t timer_interrupt(int irq, void *dev_id)
: "r" (pstate));
} while (time_after_eq(ticks, compare));
timer_check_rtc();
write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
@ -497,8 +529,6 @@ void timer_tick_interrupt(struct pt_regs *regs)
do_timer(1);
timer_check_rtc();
write_sequnlock(&xtime_lock);
}
#endif