[PATCH 4.4 38/40] rtc: snvs: add a missing write sync

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit 7bb633b1a9812a6b9f3e49d0cf17f60a633914e5 ]

The clear of the LPTA_EN flag should be synced before writing to the
alarm register. Omitting this synchronization creates a race when
trying to change existing alarm.

Signed-off-by: Guy Shapiro <guy.shapiro@xxxxxxxxxxxxx>
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/rtc/rtc-snvs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c
index a161fbf6f172..af131682dbc9 100644
--- a/drivers/rtc/rtc-snvs.c
+++ b/drivers/rtc/rtc-snvs.c
@@ -187,6 +187,7 @@ static int snvs_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	rtc_tm_to_time(alrm_tm, &time);
 
 	regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_LPTA_EN, 0);
+	rtc_write_sync_lp(data);
 	regmap_write(data->regmap, data->offset + SNVS_LPTAR, time);
 
 	/* Clear alarm interrupt status bit */
-- 
2.19.1