diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index be5a6b73e601..2bc9ef37b46f 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -40,25 +40,32 @@ static void rtc_device_release(struct device *dev) */ static struct timespec delta; +static struct timespec delta_delta; static time_t oldtime; 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(); + struct timespec ts; + struct timespec new_delta; if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0) return 0; + getnstimeofday(&ts); rtc_read_time(rtc, &tm); rtc_tm_to_time(&tm, &oldtime); /* RTC precision is 1 second; adjust delta for avg 1/2 sec err */ - set_normalized_timespec(&delta, + set_normalized_timespec(&new_delta, ts.tv_sec - oldtime, ts.tv_nsec - (NSEC_PER_SEC >> 1)); + /* prevent 1/2 sec errors from accumulating */ + delta_delta = timespec_sub(new_delta, delta); + if (delta_delta.tv_sec < -2 || delta_delta.tv_sec >= 2) + delta = new_delta; return 0; } @@ -78,6 +85,8 @@ static int rtc_resume(struct device *dev) return 0; } rtc_tm_to_time(&tm, &newtime); + if (delta_delta.tv_sec < -1) + newtime++; if (newtime <= oldtime) { if (newtime < oldtime) pr_debug("%s: time travel!\n", dev_name(&rtc->dev));