From: john stultz <johnstul@us.ibm.com>
On Wed, 2004-01-21 at 23:19, Andrew Morton wrote:
> I seem to have found a config with which my P4 test box is saying to me
> "IO_APIC + timer doesn't work! pester mingo@redhat.com".
>
>
> Disabling the ACPI PM timer in config fixes it up. I suspect the sanity
> check in there is just saying the wrong thing when we're using timer_pm?
Andrew,
I'd be interested if this patch (acpi-pm-timer-fix_B0) works for you.
It uses the pmtmr for the delay_pmtmr function, loosing granularity for
accuracy.
thanks
-john
---
25-akpm/arch/i386/kernel/timers/timer_pm.c | 29 ++++++++++++++++-------------
1 files changed, 16 insertions(+), 13 deletions(-)
diff -puN arch/i386/kernel/timers/timer_pm.c~use-pmtmr-for-delay_pmtmr arch/i386/kernel/timers/timer_pm.c
--- 25/arch/i386/kernel/timers/timer_pm.c~use-pmtmr-for-delay_pmtmr Thu Jan 22 15:26:33 2004
+++ 25-akpm/arch/i386/kernel/timers/timer_pm.c Thu Jan 22 15:26:33 2004
@@ -168,20 +168,23 @@ static unsigned long long monotonic_cloc
return ret;
}
-/*
- * copied from delay_pit
- */
-static void delay_pmtmr(unsigned long loops)
+static void delay_pmtmr(unsigned long total_loops)
{
- int d0;
- __asm__ __volatile__(
- "\tjmp 1f\n"
- ".align 16\n"
- "1:\tjmp 2f\n"
- ".align 16\n"
- "2:\tdecl %0\n\tjns 2b"
- :"=&a" (d0)
- :"0" (loops));
+ u32 then, now;
+ unsigned long loops;
+
+ do{
+ if (total_loops > ACPI_PM_MASK)
+ loops = ACPI_PM_MASK;
+ else
+ loops = total_loops;
+ total_loops -= loops;
+
+ then = read_pmtmr();
+ do{
+ now = read_pmtmr();
+ } while (((now - then)&ACPI_PM_MASK) < loops);
+ } while (total_loops);
}
_