Re: System automatically wakes up because of Intel Rapid Start Technology

From: Matthew Garrett
Date: Mon Dec 22 2014 - 13:03:01 EST


Getting this right is a little bit annoying - if the timer would have
expired during the time we were suspended, we don't want to re-enable
it. I *think* this covers all cases, and does it in generic code rather
than special-casing it. Any chance you can give it a test?

diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 472a5ad..4e3a2a1 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -91,6 +91,8 @@ static int rtc_suspend(struct device *dev)
old_system = timespec64_sub(old_system, delta_delta);
}

+ rtc->valid_alarm = !rtc_read_alarm(rtc, &rtc->alarm);
+
return 0;
}

@@ -145,6 +147,29 @@ static int rtc_resume(struct device *dev)
if (sleep_time.tv_sec >= 0)
timekeeping_inject_sleeptime64(&sleep_time);
rtc_hctosys_ret = 0;
+
+ /*
+ * If there was an alarm set before suspend, make sure that the
+ * platform hasn't overwritten it
+ */
+ if (rtc->valid_alarm) {
+ struct rtc_time tm;
+ long now, scheduled;
+
+ rtc_read_time(rtc, &tm);
+ rtc_tm_to_time(&rtc->alarm.time, &scheduled);
+ rtc_tm_to_time(&tm, &now);
+
+ /* Clear the alarm if it went off during suspend */
+ if (scheduled <= now) {
+ rtc_time_to_tm(0, &rtc->alarm.time);
+ rtc->alarm.enabled = 0;
+ }
+
+ if (rtc->ops && rtc->ops->set_alarm)
+ rtc->ops->set_alarm(rtc->dev.parent, &rtc->alarm);
+ }
+
return 0;
}

diff --git a/include/linux/rtc.h b/include/linux/rtc.h
index 6d6be09..bc805ff 100644
--- a/include/linux/rtc.h
+++ b/include/linux/rtc.h
@@ -133,6 +133,10 @@ struct rtc_device
/* Some hardware can't support UIE mode */
int uie_unsupported;

+#ifdef CONFIG_PM_SLEEP
+ struct rtc_wkalrm alarm;
+ bool valid_alarm;
+#endif
#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
struct work_struct uie_task;
struct timer_list uie_timer;


--
Matthew Garrett | mjg59@xxxxxxxxxxxxx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/