The patch titled
Subject: rtc: restore alarm after resume
has been added to the -mm tree. Its filename is
rtc-restore-alarm-after-resume.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/rtc-restore-alarm-after-resume.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/rtc-restore-alarm-after-resume.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Matthew Garrett <matthew.garrett@xxxxxxxxxx>
Subject: rtc: restore alarm after resume
Some platform firmware may interfere with the RTC alarm over suspend,
resulting in the kernel and hardware having different ideas about system
state but also potentially causing problems with firmware that assumes the
OS will clean this case up. This patch saves the RTC alarm state on
suspend and will restore it on resume if the alarm has not yet fired - if
it has, it will clear the RTC alarm.
Signed-off-by: Matthew Garrett <matthew.garrett@xxxxxxxxxx>
Tested-by: Gabriele Mazzotta <gabriele.mzt@xxxxxxxxx>
Cc: Alessandro Zummo <a.zummo@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/rtc/class.c | 24 ++++++++++++++++++++++++
include/linux/rtc.h | 4 ++++
2 files changed, 28 insertions(+)
diff -puN drivers/rtc/class.c~rtc-restore-alarm-after-resume drivers/rtc/class.c
--- a/drivers/rtc/class.c~rtc-restore-alarm-after-resume
+++ a/drivers/rtc/class.c
@@ -55,6 +55,8 @@ static int rtc_suspend(struct device *de
struct timespec64 delta, delta_delta;
int err;
+ rtc->valid_alarm = !rtc_read_alarm(rtc, &rtc->alarm);
+
if (has_persistent_clock())
return 0;
@@ -102,6 +104,27 @@ static int rtc_resume(struct device *dev
struct timespec64 sleep_time;
int err;
+ /*
+ * Ensure that the platform hasn't overwritten a pending alarm while
+ * suspended
+ */
+ if (rtc->valid_alarm) {
+ 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 registers 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);
+ }
+
if (has_persistent_clock())
return 0;
@@ -145,6 +168,7 @@ static int rtc_resume(struct device *dev
if (sleep_time.tv_sec >= 0)
timekeeping_inject_sleeptime64(&sleep_time);
rtc_hctosys_ret = 0;
+
return 0;
}
diff -puN include/linux/rtc.h~rtc-restore-alarm-after-resume include/linux/rtc.h
--- a/include/linux/rtc.h~rtc-restore-alarm-after-resume
+++ a/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;
_
Patches currently in -mm which might be from matthew.garrett@xxxxxxxxxx are
rtc-restore-alarm-after-resume.patch
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