OK, this time with Signed-off line ...
To prevent the emulated RTC timer from stopping when interrupts are
disabled for too long, implement the watchdog timer to restart it when
needed.
Signed-off-by: Clemens Ladisch <[email protected]>
Index: linux-2.6.15/arch/i386/kernel/time_hpet.c
===================================================================
--- linux-2.6.15.orig/arch/i386/kernel/time_hpet.c 2006-01-06 16:11:10.000000000 +0100
+++ linux-2.6.15/arch/i386/kernel/time_hpet.c 2006-01-08 21:31:55.000000000 +0100
@@ -413,9 +413,45 @@ int hpet_set_periodic_freq(unsigned long
int hpet_rtc_dropped_irq(void)
{
+ unsigned int cnt, ticks_per_int, lost_ints;
+
if (!is_hpet_enabled())
return 0;
+ if (UIE_on | PIE_on | AIE_on) {
+ /*
+ * The interrupt handler schedules the next interrupt at a
+ * constant offset from the time the current interrupt was
+ * scheduled, without regard to the actual time. When the
+ * handler is delayed too long, it tries to schedule the next
+ * interrupt in the past and the hardware would not interrupt
+ * until the counter had wrapped around. We catch it here.
+ */
+ cnt = hpet_readl(HPET_COUNTER);
+ /* was the comparator set to a time in the past? */
+ if ((int)(cnt - hpet_t1_cmp) > 0) {
+ /* determine how many interrupts were actually lost */
+ ticks_per_int = (hpet_tick * HZ) / hpet_rtc_int_freq;
+ lost_ints = (cnt - hpet_t1_cmp) / ticks_per_int + 1;
+ /*
+ * Make sure that, even with the time needed to execute
+ * this code, the next scheduled interrupt has been
+ * moved back to the future.
+ */
+ lost_ints++;
+
+ cnt = hpet_t1_cmp + lost_ints * ticks_per_int;
+ hpet_writel(cnt, HPET_T1_CMP);
+ hpet_t1_cmp = cnt;
+
+ if (PIE_on)
+ PIE_count += lost_ints;
+
+ printk(KERN_WARNING "rtc: lost some interrupts"
+ " at %ldHz.\n", hpet_rtc_int_freq);
+ }
+ }
+
return 1;
}
Index: linux-2.6.15/arch/x86_64/kernel/time.c
===================================================================
--- linux-2.6.15.orig/arch/x86_64/kernel/time.c 2006-01-06 16:11:13.000000000 +0100
+++ linux-2.6.15/arch/x86_64/kernel/time.c 2006-01-08 21:42:16.000000000 +0100
@@ -1234,9 +1234,45 @@ int hpet_set_periodic_freq(unsigned long
int hpet_rtc_dropped_irq(void)
{
+ unsigned int cnt, ticks_per_int, lost_ints;
+
if (!is_hpet_enabled())
return 0;
+ if (UIE_on | PIE_on | AIE_on) {
+ /*
+ * The interrupt handler schedules the next interrupt at a
+ * constant offset from the time the current interrupt was
+ * scheduled, without regard to the actual time. When the
+ * handler is delayed too long, it tries to schedule the next
+ * interrupt in the past and the hardware would not interrupt
+ * until the counter had wrapped around. We catch it here.
+ */
+ cnt = hpet_readl(HPET_COUNTER);
+ /* was the comparator set to a time in the past? */
+ if ((int)(cnt - hpet_t1_cmp) > 0) {
+ /* determine how many interrupts were actually lost */
+ ticks_per_int = (hpet_tick * HZ) / hpet_rtc_int_freq;
+ lost_ints = (cnt - hpet_t1_cmp) / ticks_per_int + 1;
+ /*
+ * Make sure that, even with the time needed to execute
+ * this code, the next scheduled interrupt has been
+ * moved back to the future.
+ */
+ lost_ints++;
+
+ cnt = hpet_t1_cmp + lost_ints * ticks_per_int;
+ hpet_writel(cnt, HPET_T1_CMP);
+ hpet_t1_cmp = cnt;
+
+ if (PIE_on)
+ PIE_count += lost_ints;
+
+ printk(KERN_WARNING "rtc: lost some interrupts"
+ " at %ldHz.\n", hpet_rtc_int_freq);
+ }
+ }
+
return 1;
}
-
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