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-rw-r--r--drivers/rtc/class.c23
-rw-r--r--include/linux/time.h1
-rw-r--r--kernel/time/timekeeping.c56
3 files changed, 63 insertions, 17 deletions
diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 39013867cbd6..4194e59e14cd 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -41,26 +41,21 @@ static void rtc_device_release(struct device *dev)
* system's wall clock; restore it on resume().
*/
-static struct timespec delta;
static time_t oldtime;
+static struct timespec oldts;
static int rtc_suspend(struct device *dev, pm_message_t mesg)
{
struct rtc_device *rtc = to_rtc_device(dev);
struct rtc_time tm;
- struct timespec ts = current_kernel_time();
if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
return 0;
rtc_read_time(rtc, &tm);
+ ktime_get_ts(&oldts);
rtc_tm_to_time(&tm, &oldtime);
- /* RTC precision is 1 second; adjust delta for avg 1/2 sec err */
- set_normalized_timespec(&delta,
- ts.tv_sec - oldtime,
- ts.tv_nsec - (NSEC_PER_SEC >> 1));
-
return 0;
}
@@ -70,10 +65,12 @@ static int rtc_resume(struct device *dev)
struct rtc_time tm;
time_t newtime;
struct timespec time;
+ struct timespec newts;
if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
return 0;
+ ktime_get_ts(&newts);
rtc_read_time(rtc, &tm);
if (rtc_valid_tm(&tm) != 0) {
pr_debug("%s: bogus resume time\n", dev_name(&rtc->dev));
@@ -85,15 +82,13 @@ static int rtc_resume(struct device *dev)
pr_debug("%s: time travel!\n", dev_name(&rtc->dev));
return 0;
}
+ /* calculate the RTC time delta */
+ set_normalized_timespec(&time, newtime - oldtime, 0);
- /* restore wall clock using delta against this RTC;
- * adjust again for avg 1/2 second RTC sampling error
- */
- set_normalized_timespec(&time,
- newtime + delta.tv_sec,
- (NSEC_PER_SEC >> 1) + delta.tv_nsec);
- do_settimeofday(&time);
+ /* subtract kernel time between rtc_suspend to rtc_resume */
+ time = timespec_sub(time, timespec_sub(newts, oldts));
+ timekeeping_inject_sleeptime(&time);
return 0;
}
diff --git a/include/linux/time.h b/include/linux/time.h
index 454a26205787..4ea5a75fcacd 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -126,6 +126,7 @@ struct timespec __current_kernel_time(void); /* does not take xtime_lock */
struct timespec get_monotonic_coarse(void);
void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
struct timespec *wtom, struct timespec *sleep);
+void timekeeping_inject_sleeptime(struct timespec *delta);
#define CURRENT_TIME (current_kernel_time())
#define CURRENT_TIME_SEC ((struct timespec) { get_seconds(), 0 })
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 8ad5d576755e..8e6a05a5915a 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -596,6 +596,58 @@ void __init timekeeping_init(void)
static struct timespec timekeeping_suspend_time;
/**
+ * __timekeeping_inject_sleeptime - Internal function to add sleep interval
+ * @delta: pointer to a timespec delta value
+ *
+ * Takes a timespec offset measuring a suspend interval and properly
+ * adds the sleep offset to the timekeeping variables.
+ */
+static void __timekeeping_inject_sleeptime(struct timespec *delta)
+{
+ xtime = timespec_add(xtime, *delta);
+ wall_to_monotonic = timespec_sub(wall_to_monotonic, *delta);
+ total_sleep_time = timespec_add(total_sleep_time, *delta);
+}
+
+
+/**
+ * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
+ * @delta: pointer to a timespec delta value
+ *
+ * This hook is for architectures that cannot support read_persistent_clock
+ * because their RTC/persistent clock is only accessible when irqs are enabled.
+ *
+ * This function should only be called by rtc_resume(), and allows
+ * a suspend offset to be injected into the timekeeping values.
+ */
+void timekeeping_inject_sleeptime(struct timespec *delta)
+{
+ 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))
+ return;
+
+ write_seqlock_irqsave(&xtime_lock, flags);
+ timekeeping_forward_now();
+
+ __timekeeping_inject_sleeptime(delta);
+
+ timekeeper.ntp_error = 0;
+ ntp_clear();
+ update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
+ timekeeper.mult);
+
+ write_sequnlock_irqrestore(&xtime_lock, flags);
+
+ /* signal hrtimers about time change */
+ clock_was_set();
+}
+
+
+/**
* timekeeping_resume - Resumes the generic timekeeping subsystem.
*
* This is for the generic clocksource timekeeping.
@@ -615,9 +667,7 @@ static void timekeeping_resume(void)
if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
ts = timespec_sub(ts, timekeeping_suspend_time);
- xtime = timespec_add(xtime, ts);
- wall_to_monotonic = timespec_sub(wall_to_monotonic, ts);
- total_sleep_time = timespec_add(total_sleep_time, ts);
+ __timekeeping_inject_sleeptime(&ts);
}
/* re-base the last cycle value */
timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);