From 585ca7254cdf4d6604ed726e0305524cfa5e3f4d Mon Sep 17 00:00:00 2001
From: Feng Tang <feng.tang@intel.com>
Date: Wed, 16 Jan 2013 00:09:47 +0800
Subject: [PATCH] --- yaml --- r: 350163 b: refs/heads/master c:
 31ade30692dc9680bfc95700d794818fa3f754ac h: refs/heads/master i:   350161:
 9f8d94c7a37638fa4ff6ebacbe9d603a526fcdb9   350159:
 85f24f6c85435326b896987a9a9237bd86c1b22e v: v3

---
 [refs]                          |  2 +-
 trunk/include/linux/time.h      |  6 ++++++
 trunk/kernel/time/timekeeping.c | 16 +++++++++++-----
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/[refs] b/[refs]
index 92abb9d4c8bb..2f00fc384075 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f0dbe81f0e7c39783ad25d9084bbcda131508993
+refs/heads/master: 31ade30692dc9680bfc95700d794818fa3f754ac
diff --git a/trunk/include/linux/time.h b/trunk/include/linux/time.h
index 0015aea4c4a7..dfbc4e82e8ba 100644
--- a/trunk/include/linux/time.h
+++ b/trunk/include/linux/time.h
@@ -115,6 +115,12 @@ static inline bool timespec_valid_strict(const struct timespec *ts)
 	return true;
 }
 
+extern bool persistent_clock_exist;
+static inline bool has_persistent_clock(void)
+{
+	return persistent_clock_exist;
+}
+
 extern void read_persistent_clock(struct timespec *ts);
 extern void read_boot_clock(struct timespec *ts);
 extern int update_persistent_clock(struct timespec now);
diff --git a/trunk/kernel/time/timekeeping.c b/trunk/kernel/time/timekeeping.c
index dfc7f87eb332..b7a584177618 100644
--- a/trunk/kernel/time/timekeeping.c
+++ b/trunk/kernel/time/timekeeping.c
@@ -28,6 +28,9 @@ static struct timekeeper timekeeper;
 /* flag for if timekeeping is suspended */
 int __read_mostly timekeeping_suspended;
 
+/* Flag for if there is a persistent clock on this platform */
+bool __read_mostly persistent_clock_exist = false;
+
 static inline void tk_normalize_xtime(struct timekeeper *tk)
 {
 	while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) {
@@ -609,12 +612,14 @@ void __init timekeeping_init(void)
 	struct timespec now, boot, tmp;
 
 	read_persistent_clock(&now);
+
 	if (!timespec_valid_strict(&now)) {
 		pr_warn("WARNING: Persistent clock returned invalid value!\n"
 			"         Check your CMOS/BIOS settings.\n");
 		now.tv_sec = 0;
 		now.tv_nsec = 0;
-	}
+	} else if (now.tv_sec || now.tv_nsec)
+		persistent_clock_exist = true;
 
 	read_boot_clock(&boot);
 	if (!timespec_valid_strict(&boot)) {
@@ -687,11 +692,12 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
 {
 	struct timekeeper *tk = &timekeeper;
 	unsigned long flags;
-	struct timespec ts;
 
-	/* Make sure we don't set the clock twice */
-	read_persistent_clock(&ts);
-	if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
+	/*
+	 * Make sure we don't set the clock twice, as timekeeping_resume()
+	 * already did it
+	 */
+	if (has_persistent_clock())
 		return;
 
 	write_seqlock_irqsave(&tk->lock, flags);