Re: Solid freezes with 2.6.25

From: Bernhard Walle
Date: Wed Apr 30 2008 - 10:50:33 EST


Hi,

* Gabor Gombas [2008-04-30 15:38]:
>
> On Tue, Apr 29, 2008 at 05:54:19PM +0200, Bernhard Walle wrote:
>
> > Hm ..., can you mail /proc/interrupts of the affected system? According
> > to the HPET specification
>
> The Intel box:
>
> CPU0 CPU1
> 0: 27346 29145 IO-APIC-edge timer
> 1: 842 819 IO-APIC-edge i8042
> 4: 2 2 IO-APIC-edge
> 6: 0 3 IO-APIC-edge floppy
> 8: 2 3 IO-APIC-edge rtc0

Well, looks fine. It's edge triggered. My assumption that the
T1_INT_STS must be cleared is wrong since the complete HPET code
assumes edge-triggered interrupts. To use level-triggered interrupts,
the HPET must be programmed in level triggered mode, i.e. the
Tn_INT_TYPE_CNF bit must be set. Which is never done.

Back to the original problem. Can you please watch the interrupts from
the RTC until the lockup happens with something like

------------------------- 8< -----------------------------------
function get_total_irqs()
{
sum=0
for n in $(grep rtc /proc/interrupts | \
sed -e 's/.*://g' | \
sed -e 's/[a-zA-Z].*//g' ) ;
do sum=$[$sum+$n]
done

echo $sum
}

last=$(get_total_irqs)
while true ; do
sum=$(get_total_irqs)
echo $[$sum-$last]
last=$sum

sleep 1
done
------------------------- >8 -----------------------------------

Also, please send the full .config (maybe via private mail if that's
too large for LKML, or upload it).

> > Can you try that patch and see if the IRQ handler is really called
> > repeatedly in that case?
>
> Unfortunately I won't have time today and will be traveling till the end
> of the week. I'll give it a shot next week.

Ok. Maybe don't use the patch I sent, instead use:



Bernhard


--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -680,6 +680,12 @@ irqreturn_t hpet_rtc_interrupt(int irq,
struct rtc_time curr_time;
unsigned long rtc_int_flag = 0;

+ if (printk_ratelimit())
+ printk(KERN_DEBUG "hpet_rtc_interrupt %s%s%s\n",
+ (hpet_rtc_flags & RTC_UIE) ? "RTC_UIE " : "",
+ (hpet_rtc_flags & RTC_AIE) ? "RTC_AIE " : "",
+ (hpet_rtc_flags & RTC_PIE) ? "RTC_PIE " : "");
+
hpet_rtc_timer_reinit();
memset(&curr_time, 0, sizeof(struct rtc_time));


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