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| author |   David Brownell <dbrownell@users.sourceforge.net> | 2008-07-23 21:30:47 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-24 10:47:34 -0700 |
| commit | 7e2a31da854dcf8324012a83a31b40bc11e52589 (patch) | |
| tree | fb982e22f3d9ac6ec2fc67a96a297dc743ef67e6 /arch | |
| parent | rtc-at91rm9200: avoid spurious irqs (diff) | |
| download | linux-dev-7e2a31da854dcf8324012a83a31b40bc11e52589.tar.xz linux-dev-7e2a31da854dcf8324012a83a31b40bc11e52589.zip | |
rtc-cmos: avoid spurious irqs
This fixes kernel http://bugzilla.kernel.org/show_bug.cgi?id=11112 (bogus
RTC update IRQs reported) for rtc-cmos, in two ways:
- When HPET is stealing the IRQs, use the first IRQ to grab
the seconds counter which will be monitored (instead of
using whatever was previously in that memory);
- In sane IRQ handling modes, scrub out old IRQ status before
enabling IRQs.
That latter is done by tightening up IRQ handling for rtc-cmos everywhere,
also ensuring that when HPET is used it's the only thing triggering IRQ
reports to userspace; net object shrink.
Also fix a bogus HPET message related to its RTC emulation.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Report-by: W Unruh <unruh@physics.ubc.ca>
Cc: Andrew Victor <avictor.za@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/hpet.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index 0ea6a19bfdfe..ad2b15a1334d 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -468,7 +468,7 @@ void hpet_disable(void) #define RTC_NUM_INTS 1 static unsigned long hpet_rtc_flags; -static unsigned long hpet_prev_update_sec; +static int hpet_prev_update_sec; static struct rtc_time hpet_alarm_time; static unsigned long hpet_pie_count; static unsigned long hpet_t1_cmp; @@ -575,6 +575,9 @@ int hpet_set_rtc_irq_bit(unsigned long bit_mask) hpet_rtc_flags |= bit_mask; + if ((bit_mask & RTC_UIE) && !(oldbits & RTC_UIE)) + hpet_prev_update_sec = -1; + if (!oldbits) hpet_rtc_timer_init(); @@ -652,7 +655,7 @@ static void hpet_rtc_timer_reinit(void) if (hpet_rtc_flags & RTC_PIE) hpet_pie_count += lost_ints; if (printk_ratelimit()) - printk(KERN_WARNING "rtc: lost %d interrupts\n", + printk(KERN_WARNING "hpet1: lost %d rtc interrupts\n", lost_ints); } } @@ -670,7 +673,8 @@ irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id) if (hpet_rtc_flags & RTC_UIE && curr_time.tm_sec != hpet_prev_update_sec) { - rtc_int_flag = RTC_UF; + if (hpet_prev_update_sec >= 0) + rtc_int_flag = RTC_UF; hpet_prev_update_sec = curr_time.tm_sec; } |