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Merge branch 'consolidate-clksrc-i8253' of master.kernel.org:~rmk/linux-2.6-arm into timers/clocksource

Browse Source 
Conflicts:
	arch/ia64/kernel/cyclone.c
	arch/mips/kernel/i8253.c
	arch/x86/kernel/i8253.c

Reason: Resolve conflicts so further cleanups do not conflict further

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner
2011-05-14 12:06:36 +02:00
parent a1c57e0fec 798778b865
commit a18f22a968
10701 changed files with 620585 additions and 295266 deletions
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76
arch/x86/kernel/i8253.c
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@@ -117,79 +117,6 @@ void __init setup_pit_timer(void)
}
#ifndef CONFIG_X86_64
/*
* Since the PIT overflows every tick, its not very useful
* to just read by itself. So use jiffies to emulate a free
* running counter:
*/
static cycle_t pit_read(struct clocksource *cs)
{
static int old_count;
static u32 old_jifs;
unsigned long flags;
int count;
u32 jifs;
raw_spin_lock_irqsave(&i8253_lock, flags);
/*
* Although our caller may have the read side of xtime_lock,
* this is now a seqlock, and we are cheating in this routine
* by having side effects on state that we cannot undo if
* there is a collision on the seqlock and our caller has to
* retry. (Namely, old_jifs and old_count.) So we must treat
* jiffies as volatile despite the lock. We read jiffies
* before latching the timer count to guarantee that although
* the jiffies value might be older than the count (that is,
* the counter may underflow between the last point where
* jiffies was incremented and the point where we latch the
* count), it cannot be newer.
*/
jifs = jiffies;
outb_pit(0x00, PIT_MODE); /* latch the count ASAP */
count = inb_pit(PIT_CH0); /* read the latched count */
count |= inb_pit(PIT_CH0) << 8;
/* VIA686a test code... reset the latch if count > max + 1 */
if (count > LATCH) {
outb_pit(0x34, PIT_MODE);
outb_pit(LATCH & 0xff, PIT_CH0);
outb_pit(LATCH >> 8, PIT_CH0);
count = LATCH - 1;
}
/*
* It's possible for count to appear to go the wrong way for a
* couple of reasons:
*
* 1. The timer counter underflows, but we haven't handled the
* resulting interrupt and incremented jiffies yet.
* 2. Hardware problem with the timer, not giving us continuous time,
* the counter does small "jumps" upwards on some Pentium systems,
* (see c't 95/10 page 335 for Neptun bug.)
*
* Previous attempts to handle these cases intelligently were
* buggy, so we just do the simple thing now.
*/
if (count > old_count && jifs == old_jifs)
count = old_count;
old_count = count;
old_jifs = jifs;
raw_spin_unlock_irqrestore(&i8253_lock, flags);
count = (LATCH - 1) - count;
return (cycle_t)(jifs * LATCH) + count;
}
static struct clocksource pit_cs = {
.name = "pit",
.rating = 110,
.read = pit_read,
.mask = CLOCKSOURCE_MASK(32),
};
static int __init init_pit_clocksource(void)
{
/*
@@ -203,8 +130,7 @@ static int __init init_pit_clocksource(void)
pit_ce.mode != CLOCK_EVT_MODE_PERIODIC)
return 0;
return clocksource_register_hz(&pit_cs, CLOCK_TICK_RATE);
return clocksource_i8253_init();
}
arch_initcall(init_pit_clocksource);
#endif /* !CONFIG_X86_64 */