---

yaml --- r: 35653 b: refs/heads/master c: 1447c27 h: refs/heads/master i: 35651: 7999729 v: v3
git-mirror · Sep 26, 2006 · 25573f1 · 25573f1
1 parent e3aad6a
commit 25573f1
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Showing 3 changed files with 63 additions and 13 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 2514183dff2d5282cb745af34f56d1b98e5b2df8
+refs/heads/master: 1447c27d38faf8fb03d4599e8082e507453ea3cf
diff --git a/trunk/arch/i386/kernel/time_hpet.c b/trunk/arch/i386/kernel/time_hpet.c
@@ -301,23 +301,25 @@ int hpet_rtc_timer_init(void)
 		hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
 
 	local_irq_save(flags);
+
 	cnt = hpet_readl(HPET_COUNTER);
 	cnt += ((hpet_tick*HZ)/hpet_rtc_int_freq);
 	hpet_writel(cnt, HPET_T1_CMP);
 	hpet_t1_cmp = cnt;
-	local_irq_restore(flags);
 
 	cfg = hpet_readl(HPET_T1_CFG);
 	cfg &= ~HPET_TN_PERIODIC;
 	cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
 	hpet_writel(cfg, HPET_T1_CFG);
 
+	local_irq_restore(flags);
+
 	return 1;
 }
 
 static void hpet_rtc_timer_reinit(void)
 {
-	unsigned int cfg, cnt;
+	unsigned int cfg, cnt, ticks_per_int, lost_ints;
 
 	if (unlikely(!(PIE_on | AIE_on | UIE_on))) {
 		cfg = hpet_readl(HPET_T1_CFG);
@@ -332,10 +334,33 @@ static void hpet_rtc_timer_reinit(void)
 		hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
 
 	/* It is more accurate to use the comparator value than current count.*/
-	cnt = hpet_t1_cmp;
-	cnt += hpet_tick*HZ/hpet_rtc_int_freq;
-	hpet_writel(cnt, HPET_T1_CMP);
-	hpet_t1_cmp = cnt;
+	ticks_per_int = hpet_tick * HZ / hpet_rtc_int_freq;
+	hpet_t1_cmp += ticks_per_int;
+	hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
+
+	/*
+	 * If the interrupt handler was delayed too long, the write above tries
+	 * to schedule the next interrupt in the past and the hardware would
+	 * not interrupt until the counter had wrapped around.
+	 * So we have to check that the comparator wasn't set to a past time.
+	 */
+	cnt = hpet_readl(HPET_COUNTER);
+	if (unlikely((int)(cnt - hpet_t1_cmp) > 0)) {
+		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++;
+
+		hpet_t1_cmp += lost_ints * ticks_per_int;
+		hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
+
+		if (PIE_on)
+			PIE_count += lost_ints;
+
+		printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n",
+		       hpet_rtc_int_freq);
+	}
 }
 
 /*

diff --git a/trunk/arch/x86_64/kernel/time.c b/trunk/arch/x86_64/kernel/time.c
@@ -1148,23 +1148,25 @@ int hpet_rtc_timer_init(void)
 		hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
 
 	local_irq_save(flags);
+
 	cnt = hpet_readl(HPET_COUNTER);
 	cnt += ((hpet_tick*HZ)/hpet_rtc_int_freq);
 	hpet_writel(cnt, HPET_T1_CMP);
 	hpet_t1_cmp = cnt;
-	local_irq_restore(flags);
 
 	cfg = hpet_readl(HPET_T1_CFG);
 	cfg &= ~HPET_TN_PERIODIC;
 	cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
 	hpet_writel(cfg, HPET_T1_CFG);
 
+	local_irq_restore(flags);
+
 	return 1;
 }
 
 static void hpet_rtc_timer_reinit(void)
 {
-	unsigned int cfg, cnt;
+	unsigned int cfg, cnt, ticks_per_int, lost_ints;
 
 	if (unlikely(!(PIE_on | AIE_on | UIE_on))) {
 		cfg = hpet_readl(HPET_T1_CFG);
@@ -1179,10 +1181,33 @@ static void hpet_rtc_timer_reinit(void)
 		hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
 
 	/* It is more accurate to use the comparator value than current count.*/
-	cnt = hpet_t1_cmp;
-	cnt += hpet_tick*HZ/hpet_rtc_int_freq;
-	hpet_writel(cnt, HPET_T1_CMP);
-	hpet_t1_cmp = cnt;
+	ticks_per_int = hpet_tick * HZ / hpet_rtc_int_freq;
+	hpet_t1_cmp += ticks_per_int;
+	hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
+
+	/*
+	 * If the interrupt handler was delayed too long, the write above tries
+	 * to schedule the next interrupt in the past and the hardware would
+	 * not interrupt until the counter had wrapped around.
+	 * So we have to check that the comparator wasn't set to a past time.
+	 */
+	cnt = hpet_readl(HPET_COUNTER);
+	if (unlikely((int)(cnt - hpet_t1_cmp) > 0)) {
+		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++;
+
+		hpet_t1_cmp += lost_ints * ticks_per_int;
+		hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
+
+		if (PIE_on)
+			PIE_count += lost_ints;
+
+		printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n",
+		       hpet_rtc_int_freq);
+	}
 }
 
 /*