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authorRafael J. Wysocki <rjw@sisk.pl>2006-09-26 10:52:37 +0200
committerAndi Kleen <andi@basil.nowhere.org>2006-09-26 10:52:37 +0200
commit34464a5b8937b79801776dfb6970c1b949fed4be (patch)
tree0e7c2ac3b792e35e036040ac39eb86f2cc466122 /arch/x86_64/kernel/time.c
parenta549b86dd0f3cbffcd5f9343f4ae7fcd59f7e756 (diff)
[PATCH] Detect clock skew during suspend
Detect the situations in which the time after a resume from disk would be earlier than the time before the suspend and prevent them from happening on x86_64. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'arch/x86_64/kernel/time.c')
-rw-r--r--arch/x86_64/kernel/time.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index 97115e608ed..9dd15d12b65 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -1039,8 +1039,16 @@ static int timer_resume(struct sys_device *dev)
unsigned long flags;
unsigned long sec;
unsigned long ctime = get_cmos_time();
- unsigned long sleep_length = (ctime - sleep_start) * HZ;
+ long sleep_length = (ctime - sleep_start) * HZ;
+ if (sleep_length < 0) {
+ printk(KERN_WARNING "Time skew detected in timer resume!\n");
+ /* The time after the resume must not be earlier than the time
+ * before the suspend or some nasty things will happen
+ */
+ sleep_length = 0;
+ ctime = sleep_start;
+ }
if (vxtime.hpet_address)
hpet_reenable();
else