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path: root/drivers/rtc/rtc-sysfs.c
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Diffstat (limited to 'drivers/rtc/rtc-sysfs.c')
-rw-r--r--drivers/rtc/rtc-sysfs.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c
index 4d27ccc4fc0..2531ce4c9db 100644
--- a/drivers/rtc/rtc-sysfs.c
+++ b/drivers/rtc/rtc-sysfs.c
@@ -145,6 +145,8 @@ rtc_sysfs_set_wakealarm(struct device *dev, struct device_attribute *attr,
unsigned long now, alarm;
struct rtc_wkalrm alm;
struct rtc_device *rtc = to_rtc_device(dev);
+ char *buf_ptr;
+ int adjust = 0;
/* Only request alarms that trigger in the future. Disable them
* by writing another time, e.g. 0 meaning Jan 1 1970 UTC.
@@ -154,7 +156,15 @@ rtc_sysfs_set_wakealarm(struct device *dev, struct device_attribute *attr,
return retval;
rtc_tm_to_time(&alm.time, &now);
- alarm = simple_strtoul(buf, NULL, 0);
+ buf_ptr = (char *)buf;
+ if (*buf_ptr == '+') {
+ buf_ptr++;
+ adjust = 1;
+ }
+ alarm = simple_strtoul(buf_ptr, NULL, 0);
+ if (adjust) {
+ alarm += now;
+ }
if (alarm > now) {
/* Avoid accidentally clobbering active alarms; we can't
* entirely prevent that here, without even the minimal