[PATCH 4.17 258/324] rtc: fix alarm read and set offset

Greg Kroah-Hartman
2018-08-23T09:03:58Z

From: Alexandre Belloni <alexandre.belloni@bootlin.com>

[ Upstream commit fd6792bb022e43faa0c4a45b6f25285e21206f9d ]

The offset needs to be added after reading the alarm value.

It also needs to be subtracted after the now < alarm test.

Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/rtc/interface.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -265,8 +265,10 @@ int __rtc_read_alarm(struct rtc_device *
return err;

/* full-function RTCs won't have such missing fields */
- if (rtc_valid_tm(&alarm->time) == 0)
+ if (rtc_valid_tm(&alarm->time) == 0) {
+ rtc_add_offset(rtc, &alarm->time);
return 0;
+ }

/* get the "after" timestamp, to detect wrapped fields */
err = rtc_read_time(rtc, &now);
@@ -409,7 +411,6 @@ static int __rtc_set_alarm(struct rtc_de
if (err)
return err;

- rtc_subtract_offset(rtc, &alarm->time);
scheduled = rtc_tm_to_time64(&alarm->time);

/* Make sure we're not setting alarms in the past */
@@ -426,6 +427,8 @@ static int __rtc_set_alarm(struct rtc_de
* over right here, before we set the alarm.
*/

+ rtc_subtract_offset(rtc, &alarm->time);
+
if (!rtc->ops)
err = -ENODEV;
else if (!rtc->ops->set_alarm)
@@ -467,7 +470,6 @@ int rtc_set_alarm(struct rtc_device *rtc

mutex_unlock(&rtc->ops_lock);

- rtc_add_offset(rtc, &alarm->time);
return err;
}
EXPORT_SYMBOL_GPL(rtc_set_alarm);