From d73406363af10b326c622a8f191a0cecadf3cbd3 Mon Sep 17 00:00:00 2001
From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Fri, 5 Sep 2008 14:05:35 -0700
Subject: [PATCH] --- yaml --- r: 109649 b: refs/heads/master c:
 4ab6a219113197425ac112e35e1ec8062c69888e h: refs/heads/master i:   109647:
 217ea37f0b05e6af211f213dc85565f8f74efab3 v: v3

---
 [refs]                              |  2 +-
 trunk/drivers/clocksource/acpi_pm.c | 46 ++++++++++++++++++-----------
 2 files changed, 30 insertions(+), 18 deletions(-)

diff --git a/[refs] b/[refs]
index fc288ded7e5a..1b8f94aa29c3 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: dfdf748a61a21b7397b9f57c83de722de71dc56a
+refs/heads/master: 4ab6a219113197425ac112e35e1ec8062c69888e
diff --git a/trunk/drivers/clocksource/acpi_pm.c b/trunk/drivers/clocksource/acpi_pm.c
index 860d033bc74f..4eee533f3f4a 100644
--- a/trunk/drivers/clocksource/acpi_pm.c
+++ b/trunk/drivers/clocksource/acpi_pm.c
@@ -21,6 +21,7 @@
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/pci.h>
+#include <linux/delay.h>
 #include <asm/io.h>
 
 /*
@@ -175,10 +176,13 @@ static int verify_pmtmr_rate(void)
 #define verify_pmtmr_rate() (0)
 #endif
 
+/* Number of monotonicity checks to perform during initialization */
+#define ACPI_PM_MONOTONICITY_CHECKS 10
+
 static int __init init_acpi_pm_clocksource(void)
 {
 	cycle_t value1, value2;
-	unsigned int i;
+	unsigned int i, j, good = 0;
 
 	if (!pmtmr_ioport)
 		return -ENODEV;
@@ -187,24 +191,32 @@ static int __init init_acpi_pm_clocksource(void)
 						clocksource_acpi_pm.shift);
 
 	/* "verify" this timing source: */
-	value1 = clocksource_acpi_pm.read();
-	for (i = 0; i < 10000; i++) {
-		value2 = clocksource_acpi_pm.read();
-		if (value2 == value1)
-			continue;
-		if (value2 > value1)
-			goto pm_good;
-		if ((value2 < value1) && ((value2) < 0xFFF))
-			goto pm_good;
-		printk(KERN_INFO "PM-Timer had inconsistent results:"
-			" 0x%#llx, 0x%#llx - aborting.\n", value1, value2);
-		return -EINVAL;
+	for (j = 0; j < ACPI_PM_MONOTONICITY_CHECKS; j++) {
+		value1 = clocksource_acpi_pm.read();
+		for (i = 0; i < 10000; i++) {
+			value2 = clocksource_acpi_pm.read();
+			if (value2 == value1)
+				continue;
+			if (value2 > value1)
+				good++;
+				break;
+			if ((value2 < value1) && ((value2) < 0xFFF))
+				good++;
+				break;
+			printk(KERN_INFO "PM-Timer had inconsistent results:"
+			       " 0x%#llx, 0x%#llx - aborting.\n",
+			       value1, value2);
+			return -EINVAL;
+		}
+		udelay(300 * i);
+	}
+
+	if (good != ACPI_PM_MONOTONICITY_CHECKS) {
+		printk(KERN_INFO "PM-Timer failed consistency check "
+		       " (0x%#llx) - aborting.\n", value1);
+		return -ENODEV;
 	}
-	printk(KERN_INFO "PM-Timer had no reasonable result:"
-			" 0x%#llx - aborting.\n", value1);
-	return -ENODEV;
 
-pm_good:
 	if (verify_pmtmr_rate() != 0)
 		return -ENODEV;